Tuesday, July 14, 2015

A Funny Thing Happened on the Way to the Vintage -- Part IV

Last week, while working on Brian Ach’s ’73 2002tii that died on the way to The Vintage, I stumbled into Rust Central. I found rust in the car’s fuel pump, gas tank, and fuel lines. I cleaned it all out and installed a new fuel pump, yet the problem persisted. I chased it into that chamber of nightmares that is the fuel injection system itself, following the troubleshooting procedure detailed in BMW’s 2002tii Fuel Injection manual. The symptoms— seeing what appeared to be bubbles of fuel and air through the translucent plastic fuel line on #4 only, having virtually no fuel come out #4 when I cracked open that line, the car not running much rougher with #4 line disconnected, and the problem not switching cylinders when I swapped delivery and suction valves—seemed to point to the problem being in the Kugelfischer injection pump itself.
Now, everyone, myself included, says to suspect the injection pump last. And that was certainly the case here, particularly since this pump had just been rebuilt by one of the five people in the country who specialize in such work. But diagnosis is diagnosis. And, with all that rust, sediment, and scale found in the fuel lines, the fuel tank, and the fuel pump, how could it not have contaminated the injection? Plus, there was the mystery of the ripped screen at the inlet of the injection pump. Had those shreds of brass gotten into the pump and bollixed it up?
As I said last week, the injection pump is a fabulous mechanical contrivance. There’s a good explanation of its functionality in the official manual for the 2002tii fuel injection system (http://www.2002tii.org/pump/pump_guide_v1.pdf), but the basic approach is “no user serviceable parts inside.” Was it even possible for rusty gas to contaminate the injection pump and cause the symptoms I was seeing? If so, could I understand the mechanism by which that could happen and fix it?
I searched on bmw2002faq.com and found a very informative thread about how a stuck piston in the injection pump could cause some of the symptoms I was seeing. The thread also said that you could unstick pistons by removing the suction valves (which exposes the tops of the pistons) and simply pressing down on them with a non-marring rod like a pencil eraser. I didn’t understand. I mean, if it’s a piston, how can you unstick it just by pressing down on it? Isn’t it rigidly attached by something like a connecting rod? But the thread also said, basically, “don’t be afraid of pulling the head off the injection pump to expose the pistons. It’s really not that big of a deal.” One of the contributors to the thread was Bill Williams, a very knowledgeable tii guy not prone to telling folks to jump off a cliff.
Symptoms fit? Source good? Procedure not a fool’s errand? Right. I’m going in.
For reams of detail on my trip in Kugelfischerpumpland, check out the technical article I wrote about it and posted on 2002faq:
Long story short (or shorter), you read about how the Kugelfisher pump is like a little piston motor that squirts fuel into the injector lines (it even uses that description in the official manual), but that’s more than a little misleading. The pump does have a camshaft with lobes, and pushrods, and little bores, and little “pistons” that run in those bores, and a head that sits on the top of the pump, making you think the rest of the pump is like a block. But it’s not. The little cylinder bores are actually in the head, not in the block. And the things that run up and down in them are referred to in the manual not as pistons, but as spring-loaded plungers. This is why you can push down on them to unstick them; they’re not rigidly attached.
(The little numbs in the pic below of the bottom end of the KFish pump are the pushrods.)

(This is the underside of the pump head showing the cylinder bores.)

(Here’s the underside of the head, upside down, with the four spring-loaded plungers in their bores.)

But, to get to the immediate point, no one tells you that the spring-loaded plungers go into the little bores from the underside of the head, so when you lift the head off the pump, the plungers and their little springs and clips simply fall out. This is, you know, kind of important. If you’re lucky, all four plungers, springs, and clips stay together and drop down inside the bottom end of the pump, which is scary but not that big of a deal as long as the springs and clips stay on the plungers (ie, big pieces of metal falling inside a Swiss watch is sort of okay because you can easily pick them out, but small pieces of metal would be really bad).
Of course if you’re unlucky like me, one of them doesn’t drop into the pump. You see something silver out of the corner of your eye, hear it go clank, and then… only silence, darkness, and pain.
Plunger overboard!
Yup, to my horror, one of them did not drop straight down into the pump. It went over the side, somewhere between the pump and the battery. Straight into darkness, as Tom Petty said. I spent hours looking in the engine compartment and on the garage floor. I jacked up the car. I felt everywhere around the top of the front subframe. I even used a borescope to look in the crevice at the back of the left frame rail (the place that swallows whole wrenches) and in the gap between the left engine mount and the steering box. I even took the alternator and its bracket completely off to be certain the plunger hadn’t fallen into the recesses behind it. Nothing.
I had decapitated someone else’s KFish pump and dropped and lost a plunger.
I was mortified.
Now, I have two old Kugelfischer pumps in unknown condition kicking around the garage. One was removed from an engine I pulled out of a rusty tii 30 years ago, cam’d and Weber’d it, and installed it into Bertha (which my friend Alex still owns). The other is from another friend’s car; he replaced it with a rebuilt KFish pump. I thought I could just yank a plunger out of one of them and rescue myself from my own idiocy. But on both pumps, some of the bolts holding on the pump head were seized. After drilling out the stuck bolts on one of the heads, I cleaned one of the plungers, and tried to put it into a bore in the head from Brian’s pump.
It didn’t fit.
What the…?
I looked on 2002faq and learned that, in fact, there are very rare racing pumps with oversized bores and plungers, but I measured the plungers I’d just removed, and this wasn’t one of them. Its plungers were very close in size to the ones in Brian’s pump, just ever so slightly larger enough that fitting them felt like forcing them.
I posted this debacle on Facebook, and in the kind of supportive action that makes you glad to be part of a tightly-knit enthusiast community, CCA member Karel Jennings responded “I have a Kugelfischer setup that came with an engine I bought years ago and installed Megasquirt onto. Want me to send you the pump head and four plungers? I have injectors as well; I’d be glad to send those too.” With a grateful response on my end, the spare pump head and plungers were on the way.
I then called Ben Thongsai (he who heals cars with his mind, and who said I should’ve convinced Brian to have his car towed to The Vintage, that we could’ve fixed it there) and picked his brain about the problem in general and the non-fitting plungers in particular. Ben said he thought it was likely that, when the KFish pumps were built, sets of plungers were probably hand-selected and hand-fitted to bores, so it was conceivable that plunger sets from one pump head might be slightly too tight or too loose for another pump head. Ben also confirmed that heads and plunger sets should swap freely between pumps—that, if I never found the fourth plunger to Brian’s original pump head, there should be no issue with swapping over the entire head and plunger set from another pump. I breathed a huge sigh of relief.
Ben also offered that, with hindsight, there were two things I could’ve tried before pulling the pump head off. The first was to remove all four suction valves, remove the KFish pump belt, and turn the pulley by hand and verify you can see all four plungers going up and down. If a plunger didn’t move, the second thing to try was, as I read in 2002faq, to push a small non-marring dowel onto the top of the plunger to free it. Hearing that, I began to think that, the rusty gas notwithstanding, perhaps Ben might have been able to work his magic had he been the one in the parking lot instead of me (pull the suction valve, press down on the plunger, problem gone, shucks, no big deal, see you at The Vintage—just the kind of thing he’d do). Unfortunately, I’d used the big hammer of yanking the pump head, so there was no way to know what I might have seen had I tried these measures (though my left brain said “crikey, all four plungers simply fell out; how could any of them have been stuck?”).
Ben and I talked about this, and he, in fact, was highly doubtful of the stuck plunger theory. He said that that stuck plungers were far more likely to be found in cars that had sat for years, and thought it unlikely that a running pump would suddenly stick a plunger while the car was going down the road.
Lastly was the mystery of the #4 fuel line. Ben couldn’t explain why I was seeing bubbles of air and fuel in the #4 injection line, but agreed that it was damned strange.
Since I could not for the life of me find the AWOL plunger, and since the head and plungers Karel sent hadn’t arrived yet, I took the head and plungers I’d pulled off one of my old pumps and prepared to swap them onto Brian’s pump. I cleaned the head, blowing out the passageways first with carb cleaner, then with compressed air. I did this for both my spare head as well as the original head from Brian’s pump, just in case his errant plunger showed its face. This was a hugely valuable exercise in several ways.
First, I learned that the head itself is dumb, really consists of nothing but passageways.
Second, in cleaning all those passageways out, I could reassure myself I was creating a clean fuel delivery environment.
Third, in cleaning Brian’s head, I did not, in fact, encounter any passageways clogged with rust and scale (e.g., no rust maggots were driven out by the cleaning).
Fourth, I saw firsthand that there’s really no way for even the most disgusting rusty mung-laden fuel to somehow contaminate the bottom end of the pump (e.g., “what happens in the head stays in the head”).
Lastly, by disassembling the pump, I could see why you can just stick a non-marring rod down the bore to move the plunger. You can look at the manual, but it makes much more sense when you actually take the head off and look at it. My losing a plunger notwithstanding, the 2002faq thread I read was right: Pulling the head off really isn’t a big deal. Next time, I’d just wrap my fingers around the back side of the head to hold the plungers when removing or reinstalling. In addition, Ben recommended a dab of Vaseline in the bores to keep the plungers in place (Vaseline dissolves in gas).
I installed the cleaned-up spare head and plungers, put in all four suction valves and the #4 delivery valve from my own tii, put everything back together, checked for leaks, and drove the car. I mentally prepared to pop the Champagne.
No difference. The car stumbled just as badly as before.
This. Is. Not. Happening.
There were three things I could do. The first was ritual suicide with a tii warmup regulator piston tool. It’s pointy and nasty. If you’re going to sever entrails and bring on slow infected death, this is the baby you want.

The second was to suck it up, take a deep breath, yank the Kugelfischer pump out of my own tii, and install it in Brian’s car. Because I was running out of things it could be.The third, of course, was to consider that my troubleshooting had been flawed. Even though it pointed to the pump, not the injectors, the fact that the #4 fuel line exhibited those weird bubbles was still unexplained. And pulling an injector is so much easier than pulling the pump. What have I got to lose?
I pulled the #4 intake plenum, removed #4 injector, unscrewed the two halves of its housing, and found… this. Although there was obvious evidence of mechanical failure, with a loose small rod and what looked like a piece of a retaining clip of some sort, at first I didn’t understand what I was seeing.

The 2002tii injection manual has the following cross section of an injector. In it, you can clearly see the lower and upper housing, the injector core, and the spring inside the core, but I couldn’t see the little rod I’d found.

I never cease to be amazed by how much I learn by taking something apart and simply looking at it. Below is the disassembled broken injector. The upper housing is on the left, then the loose rod and spring fragment, then the injector core, then the spacer and washer, and finally the lower housing.

Below is a close-up of the injector core.

Finally, below is a closeup of the core with the seat and spring pulled out of it.

For comparison, this is a view from the top of a good injector core showing the little rod in place, going through the loop at the top of the spring.

Finally, I understood. That little rod holds the top end of the spring in place. This wasn’t a broken “retaining clip.” This was the spring that the high-pressure fuel pushes against.
It was official: #4 injector had a broken spring. There was nothing holding the injector closed.
And, finally, I had a window into both the mystery of fuel and air bubbles in the #4 injection line as well as why the car was running so badly but seemed to pick up at higher rpm. The injection pump is supposed to be pushing against a closed injector, with the injector only opening when there’s 500 psi pushing on it. Instead, the injector was just flopping around. At higher engine load and rpm, the injection pump may have pushed enough fuel that some of the spurt from the pump made it through the line, past the floppy injector, into the cylinder. Just a theory. A better theory is “let’s replace this broken piece of garbage with something functional and see what it does.”
I thought… this has got to be it. How can this not be it? Can I say “eureka” now? Oh we’re close. We’re very close. I felt like I was in the Hack Mechanic equivalent of one of Sting’s year-long tantric orgasms.
More than anything, I wanted to yank one injector from my tii, swap it into Brian’s car, drive it, and see the problem solved. I thought “I could do this in 15 minutes and KNOW.” But… no. “I chased this thing down the rabbit hole,” I thought, “and the rabbit hole just branched into four. I am going to check all four branches.”
So I pulled the other three injectors.
They all were rusty.

Eur… no. Don’t say it. It ain’t over ‘till the fat lady squirts fuel.
Clearly Brian needed an injector to replace the broken one, and the others needed to be cleaned and tested. We talked about what to do. I remembered seeing a used tii motor for sale recently on Craigslist in CT for $500. Brian remembered seeing four injectors for sale on 2002faq. We agreed to follow up on both. I talked with the guy who had the motor, learned that he’d pulled it out of a car 10 years ago to install an M20 motor, and confirmed that the injection system was complete, including injectors. “What do you need to get for it?” I asked. “Well,” he said, “someone offered me $400 for it, so just beat that and it’s yours.” I PayPal’d him $420 while we were on the phone. I drove down to CT the next day and picked it up. Turned out he was a ‘CCA member back in the day, and was thrilled it was going to me.

I immediately pulled the four injectors from the spare motor. I also yanked all four from my own tii, as I wanted to get those cleaned and tested as well.
In parallel, Brian wound up buying the four injectors he’d seen on 2002faq. It took a while for him to receive them. Although they’d supposedly been cleaned and tested, with everything that had happened in fixing this car, I didn’t want to trust the testing of anything where I didn’t know the provenance firsthand.
Although it seemed like it was raining fuel injectors, I wanted belts and suspenders. I e-mailed Karel Jennings and said “you know that offer you made me to send me those old injectors? Well, funny story…”
Now, there are two schools of thought regarding having injectors cleaned and tested. One is that you need to send them to one of the five people who rebuilt Kugelfischer pumps. The other is that you can take them to any local shop that has experience with mechanical diesel or gas injectors, but you need to understand the dividing line between cleaning and testing versus rebuilding—that, if after cleaning, the injectors fail the test because they won’t open, or won’t close, or the spray pattern is bad, rebuilding them, if they’re rebuildable at all, is a specialized skill over and above cleaning and testing. I’d previously sent mine for testing to one of “the holy five,” but in truth I had no idea what had been done.
I decided to try the local diesel shop route. I found a shop in Boston who advertised that they cleaned and tested mechanical injectors. I spoke with the owner, but he said he only had the equipment to do diesel injectors. However, he said, his son had a shop in southern NH that worked with gas. I spoke with his son (Erik at Diesel’s Fuel Injection in Bow, NH) on the phone, described what I needed, and he understood completely. I sent him the three non-broken injectors from Brian’s car (labeled “known rusty”), the four from my tii (labeled “assumed good”), and the four from the spare motor (labeled “sitting for ten years, condition unknown”). Initially I thought I’d wait for Karel’s injectors to arrive and send all 15 together, but then decided, no, let’s get these 11 on their way. Plus, I thought that all Brian needed was one more good injector, and I’d just gotten four with the spare engine. What were the odds I’d need more than that, really?
In the meantime, I was doing nightly posts to Facebook and 2002faq about the status of the car. Brian posted “We’re taking it on tour! It’s the most famous poorly running tii in the country!” I retorted “Experience the full ride! For $20, hang with Rob and Brian in the parking lot of the Waffle House where it all began!”
In a week, I had the 11 injectors back. The cost for cleaning and testing all eleven was $150, which I thought was quite reasonable. The results were illuminating.

--My four were fine, which was reassuring.
--Of Brian’s three (I didn’t send the broken one), two were good, but the spray pattern on the third was bad. That meant he needed not one more, but two.
--Unfortunately, of the four from the spare engine, only one was good. The other three kept dripping. (Remember, this was cleaning and testing, with no attempts at rebuilding.)
Brian hadn’t received the four injectors he’d bought. So, incredibly, we were still short an injector. I got this news while I was at work. I immediately called Maire Anne and asked her to take the three injectors from Karel, which had arrived and were sitting in an envelope on the front porch, and send them to the injection shop. In the short term, I decided to loan Brian’s car one of my injectors. I was glad I’d just had mine cleaned and tested so we knew I wasn’t introducing another problem.
When I got home that evening, before installing the injectors, I made one more attempt to find Brian’s AWOL plunger. The battery in his car has several direct connections to it for a power amp and driving and fog lights (along with fuses and relays) that made me afraid to remove the battery for fear of yanking something out of the wiring. For this reason, I’d only searched on top of the front of the frame rail by feel for the plunger. 6th time was the charm, though; I crawled under the car, reached up there, and laid my hands right on the spring. I found the plunger and clip a moment later. I inspected and cleaned the plunger, removed my spare head and its four plungers, and reunited Brian’s head and plungers, all shiny and clean, with their original pump.

I installed Brian’s three injectors and my loaner into his car. I bolted the intake plenums back up, checked the fuel connections, then tried to start the car. It took quite a while to start, and then ran rough, presumably because of the Vaseline in the plunger bores. But then seemed to settle down into a nice even idle. I was tempted to drive it and consummate my long-delayed eureka, but it was getting late, and rather than rush through it, I decided to wait until morning when I could be fresh and step through things carefully. In order to deal with the rusty gas issue, I had replaced every rubber fuel line in the car, and I still needed to trim some of the lines to the correct length.

The next morning, I trimmed and methodically double-checked the fuel connections. When the hour was polite enough to begin cranking a car, I fired it up. Again, it started hard, but then settled down. I got in, took a deep breath, backed it out of the driveway, and drove it down the street. I fed gas in second gear at about 2000 rpm, which was the repeatable zone for experiencing the problem.
No difference. The problem remained. The car seemed to exhibit the same, or similar, lack of power until it came alive at higher rpm.
I think I turned white. I felt like someone had gut-punched me. I was clammy and sweating. My breath became short.
I pulled the car back into the garage, tried to breathe, and went upstairs for a cup of coffee. Either that or heroin. Maybe, I thought, addicts are misunderstood. Maybe they’re everyday people whose Kugelfischer systems have simply pushed them too far.
I tried to think. It kept coming back to one thing: It couldn’t be the Kugelfischer pump. I’d cleaned the head, didn’t find that it was obviously rust-contaminated, and convinced myself there was no way rusty fuel could get into the bottom end. And yet, from a diagnostic tree standpoint, it seemed that couldn’t be anything but the Kugelfischer pump.
I mentally prepared to swap injection pumps with my own tii.
No. Stop. People, myself included, have seen too many Sherlock Holmes episodes. You know, that whole “once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth” thing. There’s another much simpler possibility: You got something wrong. Or you did something wrong. Both are far more likely than the bottom end of a KFish pump, much less a freshly rebuit KFish pump, being foobar’d.
I went back in the garage and re-engaged the car.
Only now it wouldn’t start.
Oh, right, I’d forgotten that I’d pulled the connector off the cold start valve (I’ll often do this on a tii I’m troubleshooting once it starts, just to prevent it from running too rich).
With the cold start valve hooked back up, the car started, but died a few seconds later. I tried again, and again it died.
Good! I thought. This is different!
I verified that it had spark. It would start and run when fuel was spraying through the cold start valve, but then die. Clearly this was a fuel delivery problem. So calm down, forget all the recent history, and troubleshoot it like any other tii. Either fuel isn’t getting into the injection pump, or it is but the injection pump isn’t turning, or it is but something in the pump is massively mucked. Or it’s something stupid.
Let’s start with the second one. For the third time, I pulled the cover off the injection belt and verified it hadn’t slipped or snapped. It was fine.
So… fuel pressure. I hooked the pressure gauge back up, cracked the key to fire up the fuel pump, and found that wasn’t 29 psi like it should be, but was back down to 24. Must be the fuel pump or pressure valve.
I swapped the pressure valve with the KFish pump on my car. No difference.
Okay, let’s nail this. I crawled under the car and listened to the new E28 fuel pump. It sounded a little funny, like occasionally there was a bee inside it. I yanked the pump and its bypassed expansion tank (if you recall, repeated blow-outs of the expansion tank kept generating a faint haze of fine rust, indicating it was likely rusty inside, so I bypassed it). I reinstalled the pump and non-bypassed expansion tank from my own car (which I’d had the good fortune not to put back into my car yet). The fuel pressure went up to 29 psi where it was supposed to be, but the car still wouldn’t stay running.
So what was I missing?
I looked at injection pump carefully. It was behaving as if it wasn’t pumping any fuel into the injectors. I began to pull out all four suction valves to verify I’d installed the original head correctly by checking that the plungers were going up and down. When I went to loosen the Allen key cap over the first suction valve, I found that the caps weren’t tight. Apparently I hadn’t snugged them down when I reinstalled them. So I did now.
I also noticed a very small amount of fuel was weeping out of the threads of the delivery valve of #4 injection line. I tightened it.
The car immediately started and stayed running. I let it idle in the garage for 10 minutes until it was fully warmed up.
It then did the warm idle hunting (oscillating engine rpm) that tiis often do. I opened up the tuna can at the top of the intake manifold and backed out the tiny mixture screw 1/16 of a turn to richen the mixture. The idle hunting went away.
I got into the car, backed it out of the driveway, drove it down the street, punched the throttle in second gear at 2000 rpm, and held my breath.
The problem appeared to be gone.
I grinned.
I continued around the corner onto a larger street, and, ahem, drove it like I stole it. It revved joyously up toward red line.
A huge Cheshire cat smile broke over my face. I’d say “a shit-eating grin,” but, really, I’ve never understood that analogy.
I came back home, checked for leaks, found none, then took it up onto the highway. Even dropping it into 3rd at 65, running it up to five grand, and driving 80, it just purred. (These runs can be seen at https://www.youtube.com/watch?v=lEz1QoGt4zg.)
The problem really was gone.
I sent Brian a text with a single word, pregnant with meaning: Eureka!
Now I just needed to untangle the cluster of fixes I’d rapidly tried. I removed my pressure valve and put back Brian’s. Fuel pressure was still at 29, so his pressure valve was okay.
I took out my fuel pump and expansion tank and was about to reinstall Brian’s fuel pump with the expansion tank bypassed, but then I remembered the buzzing noise I’d heard. I tapped his fuel pump on a paper towel. I was surprised and less than thrilled to see some particulate matter come out. It wasn’t anywhere close to the rust mounds from the original fuel pump, but there shouldn’t have been anything. I theorized that the only part of the fuel system I hadn’t blown out with compressed air (simply because I forgot) was the fuel pickup tube itself, the part that sits inside the gas tank. Perhaps some sediment from there had gotten into the fuel pump before I’d installed the additional fuel filter between the tank and the pump, and the buzzing was the pump impeller hitting the sediment. I put the pump back in. It seemed quieter than before; I wasn’t hearing the buzzing.
Unfortunately, with Brian’s new E28 pump back in and his expansion tank still bypassed, the fuel pressure was back down to 24 psi, but despite the low fuel pressure, the car drove perfectly fine. Was it his pump or the presence of the expansion tank?  I then unbypassed the expansion tank. The fuel pressure rose from 24 to 26 psi. Still not at 29, but better. And, still, the car continued to run fine.
That evening, while it was all still fresh in my mind, I wrote Brian a lengthy e-mail reminding him that both his long metal fuel line and his expansion tank appeared to be shedding a small amount of powdery rust that should be caught by the fuel filters, but if he wanted it gone beyond the shadow of a doubt, he’d need to replace these components or pay someone to do so. And, to quote Samuel Clemens in the Star Trek Next Generation “Time’s Arrow” episode, “this increasingly hypothetical someone… would not be me.”
And then I stopped. Sometimes you need to take a step back in order to realize that you’ve completed something. I’d fixed the problem. I didn’t need to fix every problem that a 42 year old car might have.
The car had died taking Brian and his wife Michelle to The Vintage. I’d tried to fix it in a parking lot in Northern Virginia, and not only couldn’t, I couldn’t even isolate the problem. I’d failed. But that failure kicked off an extraordinary series of events. What started as an offhand comment to Brian in the parking lot (“You’ll write about this, right?” “Well, I would, but it’s the wrong ending to the story.”) morphed into an obsession. I had the power to change the ending. I just needed to do something absolutely insane and ridiculously time-consuming. Fortunately, I have long stretches where my mental state may legitimately be questioned, and time appears to still be on my side.
I had rewritten the ending to the story.
So… the mysteries:
·        Was the fuel tank ever cleaned? I think so.
·        Did the rust contamination originate with crud that was left in the gas tank, or did the car get a tank of contaminated gas? Don’t know.
·        How could the rust contamination get past the main fuel filter? Was it ripped? Don’t know.
·        Is the “black stuff” that Brian said came out of the original fuel filter the same as the “rubbery black stuff” I found in the gas tank? And where did it come from? Don’t know.
·        Did the same thing that got past the main fuel filter (assuming something did) actually rip a gash in the screen in the injection pump, or did the pump rebuilder install a gashed screen? I think the latter possibility is more likely.
·        Did the brass shards of the ripped screen muck anything up? I didn’t filter the gas and separate the crud into different sized particles. There was so much rust, scale, and particulate matter in the system that any thin brass screen fragments were almost certainly in the noise. I’d give this one a probably not.
·        Was the rust found in the injectors actually from the rusty gas, or was it unrelated? Don’t know. There are many posts on 2002faq about tii injectors getting rusty from gas just sitting in them for long periods of time. I think it’s highly likely this is what caused three of the four injectors in the spare engine to go bad.
·        Did rust and moisture cause #4 injector to break, or was that completely unrelated? Don’t know.
·        Did the Kugelfischer expert actually rebuild the injection pump? I think so.
·        Did the Kugelfischer expert actually test the injectors? Don’t know.
·        Did the Kugelfischer expert actually clean the injectors? Could all that rust have gotten in there after he cleaned and tested them? Don’t know.
·        Which of the things at the end were the cause of the car’s not running? Was it the loose suction valve caps or the small amount of weeping fuel? Don’t know. I could smell the finish line. I didn’t try to recreate the last failure to tease this one out.
·        Why did the fuel pressure never come all the way up to 29 psi? Is the new E28 fuel pump not up to snuff? Don’t know. I’ve left this one to Brian. If he wants to return the pump, I have the receipt. The car runs fine with the pump putting out 26 psi and the expansion tank in the circuit.
Man, that’s a lot I don’t know.
Alfred Hitchcock has a wonderful term: The MacGuffin. It’s the plot device that sets a chain of events in motion. Often, it’s a mysterious object. The Maltese Falcon (the bird statue in the movie of the same name) is the classic MacGuffin. The thing is, by the end of the film, the MacGuffin evaporates. If you’re a Game of Thrones fan, George R.R. Martin is a master of this. Who killed John Aryn? Who tried to have Bran murdered? Who offed Joffrey? Those were all big things that set events—even wars—into motion, yet some of them were never resolved, or if they were, by that time, it hardly mattered.
Why am I on about this? Because questions like the cause of the rust in the gas of Brian’s car and how much work was or was not performed by certain shops were MacGuffen-like. And, in the end, answering the questions mattered far less than simple thorough cleaning. In other words, “what” mattered far more than “why.”
Folks have asked me how much time it took. Initially I kept a log, then stopped, since… what was the point? I can estimate, though. Counting driving down to CT to buy the spare tii motor (which produced only one spare injector, but whose usefulness to me will hopefully play out in time), it was three full weekends and two weeks of evenings. Let’s say 3x16 + 10x3 = 48 + 30 = 78 hours. If you take 75% of that as actual on-car time, that probably puts it in the ball park.
And now, the big question: Why did I do it?
There is an entire chapter in my book devoted to the wiles of wrenching, the sensation of holding tools, the joy of being completely engaged with the repair process, the exercise of my right brain, the giving of one’s undivided attention to one problem at a time. In a world where I can’t slow global warming, fix the Greek debt crisis, or get Donald Trump to shut up, I can replace a water pump and fix a problem from start to finish, for good.
But, you know what? Despite my efforts to pare down, I still own eleven cars, and all but one need constant work. So I don’t have a shortage of wellsprings for Hack Mechanic Zen. I certainly didn’t take on Brian’s project just to have something to do.
Of course, there’s the diagnostic angle. Brian’s car was a puzzle. The puzzle was fun. The puzzle completely occupied me for three weeks. But is that why I did it?
Would I have done it had I known how much work it was going to be?
Probably not. 

But if I knew that, I would’ve known what the problem was. Sorry. If you’re going to play “what if,” you can only alter one reality at a time.
Look. We are complex entities. We do all sorts of things for all sorts of reasons. In the end, this was not unlike my replacing the engine in my friend Alex’s piece of crap Passat wagon. It was what needed to be done to help out another human being. Alex is, in many ways, my closest male friend, and he was flat broke at the time. In contrast, I’ve only had three hours of face time with Brian in a hot parking lot. But we connect with the people we connect with. I liked Brian. I liked his wife. I liked the way they treated each other. I felt for him and the personal inescapable Kugelfischer-related hell he felt he was in trapped in, never being able to fully solve the problem with the car. I was in a position to help him. So why not help him? Did it really need to be more complicated than that?
In the end, really, I have no better answer than this one. I only wish I looked as good in a white muscle shirt, suspenders, and a brown fedora.

(Next week: The Hack Mechanic finds something more productive to do with his time. Maybe installing that spare tii engine in the Lotus Europa. Too bad it needs fuel injectors.) –Rob Siegel

(Epilogue: The fuel injection shop just called me with the news about the three injectors Karel sent me. They’re empty. They’re upper and lower housings that have no injector cores in them. Karel and I had a good laugh. “I’ve had them in a box in the basement for ten years thinking they were worth something,” he said. So, in finding usable injectors, I’m one for seven. Brian is Fedexing me the four he bought. Hopefully his success rate will be better.)

Got a question for Rob Siegel, the Hack Mechanic? You can find him in the BMW CCA Forums here!

Rob’s book Memoirs of a Hack Mechanic is available through Bentley Publishers, Amazon, and Bavarian Autosport—or you can get a personally inscribed copy through Rob’s website: www.robsiegel.com.

(copyright 2014, BMW CCA, all rights reserved)

Wednesday, July 8, 2015

A Funny Thing Happened on the Way to the Vintage -- Part III

When we ended last week, Brian Ach’s recalcitrant stumbling stuttering ’73 2002tii that betrayed him and his wife Michelle in northern Virginia on the way to The Vintage had been towed to my house in Massachusetts. I’d offered to fix it. For free. So I could rewrite the ending to the story where I’d failed to fix it on the road. My plan was to throw equal parts logic, ego, and components stolen off my own tii at it until it or I cried uncle.
It seemed like a good idea at the time.
Now, there’s an expression in troubleshooting: Plan the work, work the plan. For a tough problem, take your emotions out of it. Don’t follow pet theories. Don’t take shortcuts. Sure, prioritize things that are more likely, and leave the ugliest least likely most expensive possibilities for last, but develop a systematic approach and execute it. If the approach is sound, you’re highly likely to solve the problem, sometimes in spite of yourself. So my plan for to finding and fixing the problem in Brian’s car was this:
·        Do a compression test to rule out anything mechanical and catastrophic.
·        Adjust the valves while the engine is cold… because adjusting valves makes me feel connected with a car.
·        Check that the TDC mark on the front of the crankshaft agrees with the one on the flywheel. (Paul Wegweiser’s crankshaft pulley was once installed backward, and the two marks were off from one another.)
·        Check that, at TDC, the camshaft mark lines up with the mark in the head.
·        Recheck the mark on the pulley of the Kugelfischer pump to verify it also lines up correctly.
·        Recheck the dynamic ignition timing and the basic advance functionality of the distributor
·        Verify that the voltage at both the battery and the coil is about 14 volts with the engine running and doesn’t vary much with engine RPM.
·        Drive my tii and verify that it runs correctly.
·        Drive Brian’s tii and verify that the problem still exists.
·        Swap the entire ignition system from my tii – dizzy, Pertronix, cap, rotor, coil, resistor, plugs, plug wires, everything.
·        If the problem goes away, begin swapping ignition parts back until the problem reappears to determine which component is bad.
·        If, instead, the problem persists, start to do something similar with the fuel system. Don’t swap everything right off the bat because pulling two Kugelfischer injection pumps and eight injectors and swapping them is a bit of a pain. Plus, the injection pumps are extremely reliable; when you hear hoof beats, think horses, not zebras and all that.
·        Start with the fuel pump – logical, since Brian’s had low fuel pressure (24 psi where it should have 29). Check fuel volume as well.
·        If necessary, use my portable exhaust gas analyzer to see what the thing is doing (rich or lean) when it’s running terribly.
·        If necessary, use an IR thermometer to help locate a weak performing cylinder.
·        If that doesn’t work, look at the gas, draining the tank and trying clean branded gas if necessary.
·        If that doesn’t work, systematically go through the entire fuel system.
·        If that doesn’t work, read up on how to cover up insurance fraud.
I was a man with a plan.
But if you asked me what I thought… There’s that old saying “your fuel problems are in your ignition.” Always suspect the ignition first. Plus, Brian’s fuel system was known good.
With that sly opening, let me offer a meditation on the concept of known good. Because if you don’t understand this, you can’t truly appreciate how weird the events that unfolded were.
About two years ago, during a general sort-out of my own tii, I was having terrible problems. I’d just had the distributor rebuilt by a highly reputable shop, and installed it and a new Bosch Red coil, the correct matching Bosch Red ballast resistor, new plugs and plug wires, and new points and condenser, the latter two procured from a BMW dealer in BMW logo’d boxes with BMW part numbers. But the car ran horribly. With all those new ignition parts, it clearly seemed to be a fuel problem. I posted my trials and tribs. My friend Lindsey Brown, a pro, texted me. “Can I come over and play?” he asked. He showed up with a distributor that looked, shall we say, experienced. “This,” he proclaimed, “is known good. I pulled it out of my own running 2002 this morning. Let’s put it into your car.”
“How can you say,” I retorted,” that that’s known good? MY distributor is known good. It was just professionally rebuilt. The points and condenser are brand spanking new. It’s certainly more known good than yours. It can’t be the problem.”
“Are you or are you not having a problem you can’t figure out?”
“Well… yes.”
“Then humor me,” he said. “Let’s put in my distributor and see what happens.”
My response was, essentially, “grumble… bitch… gripe… I’ll show you known good.
We removed my essentially new dizzy and replaced it with Lindsey’s beat-up-looking one. I started my car. The problem was gone. I picked my jaw up off the floor.
“Now,” said the professional, “let’s transfer one component at a time from your distributor onto this one until we find out what is actually causing the problem.
It turned out that the culprit was the brand new condenser that I’d purchased from a dealer in a BMW logo’d box. It lasted about five miles before it died.
It was in this experience that I learned what was probably the most important diagnostic lesson in my Hack Mechanic life: There is no known good. There is only diagnosis.
Let that one seep into your bones for a few weeks until it’s part of your DNA. I’ve experienced this same thing in my engineering career, but it usually takes a slightly different form: Whenever you say “it can’t be X,” you’re admitting you have a blind spot surrounding X. Remove it. Because it may well be X and you need to be able to see or at least consider that.
Next, you must permit me a Star Trek moment. In the “Wink of an Eye” episode, Kirk and another crewman are kidnapped and taken into an accelerated timeframe. They move so quickly that they can’t be seen by the non-accelerated crew, only perceived as a faint buzzing. Kirk tries to communicate with the crew by recording a message and leaving it in what can only be described as the Enterprise’s 8 Track tape deck. Spock finds it and listens to it, but the tape contains only buzzing. At some later point, after the crew finds structures built around the Enterprise’s engines with no visible evidence of people, only buzzing, the light bulb goes on for Mr. Spock. He hears the buzzing again, and he says to McCoy “I know what it is.” He’s figured the acceleration thing out. He retrieves the tape, slows it down, and can now hear the captain’s message.
The point in all that geekiness is that, most of the time, we don’t get to say I know what it is, which appears to be the Vulcan equivalent of eureka. It’s really rather rare, at least for me, to look at and think about a car problem and engage it so rationally that it leads me inexorably to a path where I do one test, go “a-HA!” know that I’ve found the answer, and pat myself on the back for my diagnostic skills. Most of the time, you just need to pound it out. And, by the time you do, you’re often robbed of that “eureka” moment because you’ve spent a boatload of time and money, you’re tired, and instead of eureka, your reaction is often “THAT was it? You have got to be shitting me.”
I began to execute the plan. I did the timing and voltage checks. It made no difference. I then drove my tii and verified that it ran fine. In one of those big circle of life things, my distributor that had been thought good but actually bad was now the one that was known good, or as close as you can get. I put the two cars nose-to-nose in the garage like a rotated scene out of Frankenstein. I pulled the ignition out of Brian’s car and put it in a box. I then yanked the entire ignition – everything – out of my tii and installed it into Brian’s. As I was doing so, I had the thought “you know, this is really too big of a chunk to do at once. Plugs and plug wires, coil and resistor… probably not necessary. You’re going to have to swap them back when you start this puppy up, drive it, and the problem is gone. You probably should’ve swapped only the dizzy and its components.”
But, hey, plan the work, work the plan, right? Everything was swapped, I started Brian’s tii up, pulled it out of the garage, drove it around the block, and…
No difference.
Well, then. Wasn’t that cagey of me to misdirect you by floating three times how much I regretted not having had a distributor with me when I looked at the car in the parking lot? In truth I had regretted it, right up until this moment when I realized it would’ve made no difference.
I came inside and told all this to Maire Anne. She’d heard me explaining “the plan.”
“So,” she said, “that means it can’t be an ignition problem, right?”
I was careful.
“No,” I said, “it means I don’t see how it could be an ignition problem.” Remember—try not to have blind spots.
The path was clear. If it’s unlikely to be ignition, look at fuel. This meant engaging The Mystery:
·        The entire fuel system was supposedly “known good,” with the injection pump, injectors, fuel pump, and gas tank all serviced 700 miles ago.
·        The Kugelfischer injection pump had been rebuilt and the injectors cleaned and tested by one of the five experts in the country who specialize in this work. Unless some unspeakable fate befalls an injection pump, it should be the last thing you should when a tii goes from running to not running or running poorly.
·        The gas tank had supposedly been cleaned, yet when Brian pulled out the fuel filter in the parking lot and tapped it out on a paper towel, “black stuff” came out of it.
·        The small brass screen at inlet of the injection pump had a big tear in it. So either the pump rebuilder had installed it that way, or something had muscled its way through the fuel filter and ripped the screen. Both possibilities were unsettling. Brian’s nightmare scenario was that the small brass threads of the screen had gotten into the injection system and were mucking up the pump and/or injectors.
·        The E28 fuel pump—also installed only 700 miles ago—was putting out low fuel pressure, 24 psi instead of 29.
Since the fuel pump pressure was low, addressing it was not only the obvious next step, it seemed the next most likely source of the problem. I realized that I didn’t even need to pull the fuel pump out of my tii—I’d prophylactically replaced mine with an E28 fuel pump last year and had my original fuel pump sitting on a shelf. I undid the fuel lines and the three 10mm nuts holding the fuel pump assembly (the bracket, pump, and its expansion tank about the size of a small pickle jar) in Brian’s car and pulled it out as a unit. I removed his newly-installed E28 pump and installed my old tii pump. I tightened everything up and turned the key to fire up the pump so I could check for leaks.
Gas everywhere.
I shut it off and rechecked the hoses. They were all tight. I looked at the fuel pump carefully, and fuel seemed to be leaking from around the electrical plug itself, rather a terrifying sight. I pulled it all out, took the pump out, cleaned it and dried it, and blew into the inlet. Sure enough, bubbles came out around the connector. My old fuel pump was cracked. Sheesh.
Try this again. I crawled under my tii, pulled out my pump assembly, and swapped it en masse into Brian’s car. I spliced a fuel pressure gauge in the engine compartment with a tee fitting. I cracked the key and checked for leaks. Tight. I checked the pressure. 28 psi—much better. I fired up the car, backed it out of the garage, and took it down the street.
No difference.
This was the first of many anti-eurekas. (e.g., “That wasn’t it? You have got to be shitting me.”)
Okay then. It was time to listen to my own there is no known good advice, as well as all the folks who had chimed in saying “go back to basics and check the gas tank.” I undid the eight bolts holding the filler flange onto the tank and pulled out the pickup assembly. There’s a screen at the bottom of the pickup tube. The screen had a small amount of particulate matter in it, but nothing alarming. I also noticed that the screen wasn’t sitting completely flush with the bottom of the tube, as if it had been pried out, cleaned, and put back in slightly askance. This wasn’t a big deal. If anything, it said to me that the tank and the screen had likely been cleaned.

I then looked into the gas tank with a flashlight. In the recess at the bottom where the pickup tube sits, I saw a small amount of particulate matter. I’d done this same thing with my own tii two years ago, and what I found in it was horrifying; it looked like pot roast. What I saw in Brian’s tii struck me as minor. Just a little bit of rusty scale. And some odd black bits. I fished a few out. They were soft, unlike the rust, but I couldn’t tell if they were paint that had fallen off the outside of the tank and had found their way in, or pieces of the inside of a fuel hose that had been degraded by ethanol, or what. I thought about Brian’s observation that “black stuff” came out of the fuel filter in the parking lot. Was it the same stuff? There was no way to tell.
I thought that, given the persistent nature of the problem, I’d be wise to do a front-to-back component-by-component check of the fuel system, skipping no steps and leaving nothing to chance.
It was the best diagnostic decision I’d ever made.
I undid the fat rubber fuel hose that connects the pickup tube to the inlet of the fuel pump and let the gas run out into a clean bottle. I then blew out the hose with compressed air into the same bottle. When I looked at the bottle, there was a surprising amount of rust, scale, and particulate matter in it. What the…? If that came out the hose that was between the gas tank and the pump, then…
I grabbed the E28 fuel pump I’d removed from Brian’s car. Original tii fuel pumps have a small screen at the pump inlet that keeps rust and other gas tank crud out of the pump, but E28 pumps apparently don’t. I looked inside the inlet, and saw some brown stuff. I swabbed it with a few Q Tips, and immediately pulled out some sizeable rust flakes.

I wondered if that was the tip of the rustberg. I began tapping the inlet of the pump on a paper towel. A horrifying rust mound quickly formed.

I let it rest for a while, then repeated. More rust continued to come out.

So, rust had gotten past the pickup screen and into the E28 fuel pump. I would’ve screamed eureka, but it hardly seemed appropriate. I’d already changed the fuel pump and it made no difference. And the questions. Was the rust from the pre-cleaned gas tank? From a single bad tank of gas after all the work had been done? I didn’t know. I asked Brian about the exact order in which all the known good work had occurred. In fact, it wasn’t all at the same time. In one thrust, the fuel tank was cleaned, and the rebuilt injection pump and cleaned and tested injectors were installed. But the E28 fuel pump was apparently installed earlier. This made some sense. It meant that rust from the pre-cleaned tank could’ve gotten into the screen-less E28 fuel pump and hung out in there, still present even after the tank and injection components were cleaned.
The question was how far forward in the car the rust had gotten. Had the E28 fuel pump acted like a food processor, grinding up the rust and spitting it into the injection system? I removed the main fuel filter by the battery—the one Brian had installed in the parking lot in Virginia, then driven perhaps 40 miles on while nursing the stumbling car to where he could rent a U-Haul trailer and truck. I tapped the filter on a paper towel, and only clear gas came out. Again, this was the replacement filter. The previous filter was the one where Brian reported that “black stuff” came out when he tapped it on a paper towel. Well, whatever had happened had happened, but it was clean now, and there was no evidence now that rust was getting past it into the engine.
Still, I wanted to be thorough, so I used compressed air to blow out the line from the inlet of the filter all the way to the back of the car. Note that this line consists of a hard metal line that runs underneath the car, with a short rubber hose on each end. I captured the blow-out in a bottle.
I was greeted with a horrifying combination of rusty scale, sediment, and powdered rust.
Known good my ass.

I blew the line out probably ten times trying to get it clean, spraying carb cleaner in one end, and using a rag held on the other end with a hose clamp, and still kept getting a faint halo of rust on the rag.

A new mystery presented itself: How could all this crap come out the line, yet none of it be present in the fuel filter? I theorized that, since the tii’s fuel filter is mounted vertically next to the radiator, it was possible that lose crud could come into the filter and get blocked, but when the fuel pump was shut off, gravity could cause the gas and crud to simply drain out the bottom of the filter into the fuel line beneath it, and accumulate there.
I also theorized that there were probably at least three separate issues. The big rust was likely from the original unclean tank or a load of bad gas, whereas this fine powdery stuff I couldn’t get rid of was likely because there was rust forming on the inside of the long metal line itself, as well as inside the metal expansion tank. I blew the metal line and the tank out, individually and repeatedly, and always saw a faint rust halo on the rag.
There was one more fuel line—the return line from the pressure valve on the back of the Kugelfischer pump to the gas tank. I did the same test, putting a bottle on one end and blowing compressed air into the other. This line showed up clean as a whistle. This was good—there was no evidence of rust making the round trip back to the tank. And with no rust coming out of the main fuel filter, that meant there was no direct evidence anything had gotten into the Kugelfischer pump or the injectors. At least not yet.
Finding all this rust may not have deserved a eureka, but how could it not affect the car’s running? How could the car not run better with it all cleaned out? I put everything back together and drove the car.
No difference.
Okay. Okay. There was one more thing to try before zeroing in on the challenging and expensive issues of the Kugelfischer injection pump and the injectors. That was the gas itself. One school of thought is that an additive containing alcohol can break up the water, allow it to mix with the fuel and be burned, but the other school of thought is that, if you have water in the gas, there’s little alternative but to drain the tank.
Rather than wonder about it, I just did it.
Fortunately, 2002s have small (10 gallon) tanks anyway, the tank was less than half full. I took the old E28 fuel pump—the one that had all the rust in it—wired it to a battery, and used it to pump out most of the gas into a gas can. I then manually cleaned the bottom of the tank with rags until it was visibly free of scale and particulate matter. Again, it didn’t really look all that bad to me. It seemed to me likely that the tank had been cleaned, but some load of particulate matter came in, perhaps with a fill-up. But wherever it had originated, I cleaned it up.
For a moment, I thought “you know, now that it’s drained, if I remove a few bolts, I could pull the gas tank completely out of the car and have it professionally cleaned.” But I didn’t know that the tank, or bad gas, was in fact a problem, much less the problem, and I didn’t want to wait a week for the tank to be cleaned and reinstalled to find out. Instead, I drove to AutoZone, bought a brand new clean 5 gallon gas can and a generic high-pressure fuel filter, drove to a branded gas station, bought a few gallons of branded 93 octant gas, dumped it into the cleaned tank, installed the generic fuel filter between the tank and the fuel pump (which was now my fuel pump out of my tii) to reduce the possibility of any stray particulate matter from the tank getting into the fuel pump, and drove the car.
No difference.
My future seemed to ineluctably involve a Kugelfischer injection pump and injectors.
Then I got a call on an unrelated matter from my friend Tom Samuelson. Tom has eclectic car tastes. He has a killer E9 and an E24, but also a beautiful E Type convertible, a Volvo P1800, and a hot rod. Sometimes cooking in a bunch of different kitchens gives you better perspective on problems. I explained to Tom what I’d found.
“Hmmn,” he said, “Kind of sounds like an ignition problem to me.”
“That’s what I thought,” I said, “but the diagnosis hasn’t borne that out.”
“Was anti-seize paste ever used on the plugs?”
“I don’t know. Why do you ask?”
“Well,” he said, “I’ve seen it cause intermittent grounding of plugs, translating into weak spark.
It fit the symptoms. I texted the question to Brian. “You know,” he said, “in fact, yes, I did use anti-seize on the last set of plugs.”
Bingo. And thus we see the value of knowing the difference between “it can’t be an ignition problem” and “I don’t see how it could be an ignition problem.” The latter leaves room for anti-seize paste; the former does not.
I called back Tom. “What do you use to get it off?”
“Acetone and a toothbrush.”
This was perfect. There’s a Rite-Aid next to Bentley Publishers. At the end of the day, I walked next door and bought some acetone nail polish remover and a toothbrush. I could barely contain my enthusiasm as I drove home. I didn’t even head inside the house; I went straight into the garage. I pulled the plugs and cleaned them and the plug holes with acetone. There wasn’t much residue, but, hell, who knows. I cleaned it all up, put it together, drove the car, and…
No difference.
I’d always thought that Brian’s worst fear about there being brass screen fragments inside the injection was highly unlikely. Now, even though I still had no direct evidence that any contamination had gotten past the main fuel filter, I didn’t know what to think. There really didn’t seem to be much else it could be other than the injection pump and/or injectors. And whether they’d gotten contaminated by rusty fuel or by screen fragments didn’t seem to affect the course of action. Either way, I needed to look at the pump and injectors.
The Kugelfischer injection on the 2002tii has the reputation of being arcane and impenetrable, but in fact it’s quite well documented. The injection pump itself is often referred to as a Swiss watch of engineering. Back in the day, BMW of North America published a slim volume “The BMW 2002 tii Fuel Injection System” intended for service technicians. It’s available for download on Bob Murphy’s 2002tii site at www.2002tii.org/pump/pump_guide_v1.pdf. The manual largely treats the injection pump as “no user serviceable parts inside,” but, to continue the Swiss watch analogy, there are four small Allen key covers on the top of the pump, and beneath them are four little suction valves that look remarkably like little watch batteries (e.g., sure, pop the back off the watch to change the battery, but don’t even think about touching anything else inside). There are also four delivery valves screwed to the top of the pump. The injection lines are attached to the delivery valves. The manual does a nice job leading you through a rough-running troubleshooting exercise to isolate  the problem to a cylinder, and from there to the suction valve, delivery valve, injector, or, by default fall-through, the pump. It essentially says:
·        First, make sure it’s a fuel problem and not an ignition problem.
·        One line at a time, use a 14mm wrench to slightly loosen the connection of each fuel line to each delivery valve. Fuel should immediately come out the loosened line, and the engine should run noticeably rougher. If it does, that cylinder is probably not the problem.
·        If fuel leaked out but the engine doesn’t run rougher, the problem is likely either the delivery valve or the injector. Swap delivery valves between cylinders to see if the problem stays with the delivery valve or the cylinder. If it stays with the cylinder, it’s likely the injector. Swap injectors and retest.
·        If no fuel leaked out, the problem is likely either the suction valve or the injection pump. Swap suction valves between cylinders to see if the problem stays with the suction valve or the cylinder. If it stays with the cylinder, it is likely an internal problem with the pump.
I went through this exercise and found that, when I cracked open line #4, no fuel leaked out.
A-HA! Finally! Got you, you little sucker!
Following the troubleshooting procedure, I undid #4 Allen key cap and pulled out its suction valve. The underside had a red powdery coating on it. I immediately removed the other three suction valves and checked them. They all looked similar. This appeared to be the first direct evidence that rusty fuel had in fact made it into the injection system. This was big.
(I’m not sure what happened with this photo, but you can still make out the slight rusty cast on the valves.)

Almost giddy with the discovery, but biting my tongue to not shout “EUREKA” and anger The Hack Mechanic Powers That Be, I thought “to hell with swapping #4 suction valve with #3. I’m swapping all four suction valves with the, ahem, known good ones from my tii and driving the car.” I had a moment where I thought “no, don’t do this. Don’t skip a step. And don’t risk contaminating your own injection system with rust.” But I could smell victory. And I reassured myself that I’d thoroughly blown out every fuel line on Brian’s car, and the risk of cross-contamination was negligible.
I swapped all four suction valves with those from my tii and drove Brian’s car.
It made no difference.
Unbelievable. Unfreakingbelievable.
I repeated the “crack the line” test. #4 still had no fuel coming out. If I had a “known good” suction valve in there, by the troubleshooting procedure in the manual, this meant the problem was likely in the injection pump itself.
I felt like I was at the scene of a train wreck. I tried to gather my wits and soak it all in. I started the car, and looked, and listened.
I said that, back when I was checking out the car in the parking lot in Virginia, “I put a finger on each of the plastic injector lines and verified that I thought I could feel fuel pulsing into them.” With this new knowledge about #4 pump line apparently not outputting fuel, the validity of that observation was clearly in doubt. I again put my finger on #4 line. Could I feel pulsing, or was it just sympathetic vibrations from the other lines? I couldn’t tell.
But, then, I saw something. The fuel lines are translucent plastic. And #4 line looked different than the other three. With the car running, I could see nothing in the other three lines, but #4 looked like, well, like when you slurp liquid and air up a straw from the bottom of a glass. That is, I could see what I assumed to be both fuel and air in #4 line but not in any other. It wasn’t right. Plus, how was it that I could crack the nut holding #4 line and not have fuel come out, but see fuel in the line?
It didn’t make any sense.
The fuel pressure in the lines coming out of the Kugelfischer pump is supposed to be very high, about 500 psi. In a “kids don’t try this at home” moment, with the car running, I completely undid #4 line from its delivery valve and watched. There were small upward spurts of fuel out the delivery valve, but it didn’t look like the 500 psi Vesuvius I’d imagined.
Something appeared clearly wrong with the fuel delivery from #4 port of the injection pump.
So much for horses not zebras.
Did I mention that I was doing this for free, in an attempt to change the ending of a story—this story—from “I failed” to “yeah, I kick ass?”
Okay. I’m going in. In the immortal words of Groundskeeper Willie, “Lunch lady Doris, have you got any grease? THEN GREASE ME UP WOMAN!”

(Next week: The Hack Mechanic goes in, and lengthens his list of life’s regrets.)

(copyright BMW CCA 2014. All rights reserved.)