Engine runaway, VW dealer says bad IP?

jasonTDI said:

NOT TRUE!!!! Seen MANY injection pumps take out rods. Happens WAY MORE than you'd think.

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Not only this, the injection pumps CAN get taken out by overspinning due to the runaway. IT's rare but it can happen. I'm pretty sure the pump is unhappy when you've overspun it past the redline. Without the tach showing it (I've got a gasser tachometer), what do we think the rpms are at when its running away for a good 10-15 seconds?

Sorry Abacus

First, he said a second or two, not 10-15.

Second, tunes can be had that increase the redline to 6k rpm and that doesn't seem to have an adverse effect.

So unless people start posting up proof that shows it's more than just a Blue Moon frequency, the supposition and chances it'll happen are getting pretty thick. It's possible the fuel filter could break apart and ruin the pump too, do people want to add that into the basket? How about lines collapsing due to the vacuum created?

We can go on all day. I'll concede a pump can cause a runaway (based on OH's experiences) if you people concede 99.9% of the time they don't and it's due to oil ingestion.

Continued...

So I have the motor in my car from the parts car. I did not find out till after it was installed that it had been running on B100 biodiesel for years. Seller put a tank of diesel in it just to sell it. Nice, huh?
Anyway, I have a few things to work out with this motor now. I have a P1562 code (QA upper limit) w/ flashing glow plug light. Also a convenient coolant leak at the water pump. I was also told the TB had been changed 10k ago. Also a lie. I bought the wrong motor!
So I started tearing it down. I am cleaning the intake, EGR (both super clogged) and intercooler. I want to tear down the IP, clean it, diagnose P1562 code and reseal. I will also have to do a full timing belt job. It will get new air and fuel filter as well. Is there anything else I should check over or clean out due to running biodiesel while it's tore down?
Also, I have the old motor/IP for parts, but not sure whats bad from the runaway. Is there any way of testing an IP with it off the car? Is there a best way to test QA function for both the old and the installed pump? Before I tore it apart (I should've checked closer) I think the actual injection quantity was 3.2, which should be in spec? although the motor was not warmed up.
Hind sight is 20/20, I should've just waited to find a better replacement engine

"QA upper limit" generally means the quantity adjuster inside the IP is having a hard time moving thru its entire range of motion.

If you've got the pump apart and are giving it a good cleaning you'll likely uncover whatever is gunking up the adjuster.

This isn't related to the IQ setting in VCDS per se.

Thanks for the reply. Would it be a better idea to do the t-belt and fuel filter including thermo-T and put everything back together to better diagnose the pump before I tear into it? Or should I do it while I have the belt off in case the pump has to come out?

That code can also be set by the timing being out of spec. I'd do the timing belt job then recheck.

ABSOLUTELY a bad pump can cause a runaway. I think Kerma had a thread about it, a piece inside breaks and cause's the runaway. The pumps usually sound very marbley before they fail.

*Update*
Almost everything is back in order - check engine light for EGR and QA upper limt and flashing GP light are gone! I ordered some tools and did the timing belt job, including the water pump, thermostat, fuel filter w/ tee, air filter, oil filter, new oil, and new coolant. I set timing between blue and green lines in VCDS. IQ was quite low - around "2" now. It would not let me adapt in VCDS. EGR excessive and QA limit codes still there at this point. Ordered seals for the pump. Man was this thing gunked up! The QA was completed coated in a layer of black "gunk" over 1/16" thick.. I will add pic below. I'm almost sure this is the result of running homemade biodiesel, or worse grease lol. The qa arm did not have fill range of motion, and the sliding control collar was also a bit sticky at the end of its travel. Cleaned it all up and installed the 3 main seals. I did not remove the QA from the housing to see the electromagnet etc, but there were no metal shavings at magent, and could see clean coils throught the little hole, so I left it alone. Primed pump, started, and adjusted IQ. Running good, so I cleared my codes and took it for a drive. The before instant check engine at startup is gone, and stayed off for the drive. Awesome! Let's hope it stays that way!
The only issue left is my air flow specified VS actual. They should be close, but specified (at idle) is 280 and actual is 480. Duty cyce is either around 5% or 85%. I have switched out all the vacuum control valves with spares and still the same. No codes for it. Even switched out the MAF for a spare and still the same values. Actual is always about 200 more than specified at higher rpms. I just cleaned the intake and EGR, and that EGR code is gone (only for one drive so far). I do have a vacuum leak I am working on fixing, can this cause it? Does the turbo affect these numbers? Or is it likely both the MAF sensors I have are bad?

Holy crap!!!!
What did you use to clean it?

Haha I can't believe I was able to get it clean. Should have got an "after" shot.. Patience my friend, mostly. Brake cleaner, tiny screwdriver, wire brush, and compressed air. I removed just the fuel temp sensor and black plastic part next to it and was able to get 95% of it out. Didn't want to mess with soldering the board and realigning the arm etc.. even underneath the qa housing was caked. I had to be slow and careful not to drop the stuff into the pump.

How did it look in the pump body itself? Same goop?

No, actually.. It looked pretty good.. Everything past that hole was drastically cleaner. possibly bc it's always submerged in fuel? As it leaked, the fuel level in the pump would drop leaving fuel to dry out on the upper components leaving this residue behind.. maybe? It almost has a fiber like consistancy. Maybe that grade-A B100 was eating up fuel filter media lol. Nasty stuff.

This is great thread in many ways!

UhOh said:

This is great thread in many ways!

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Yes, lots of experienced and knowledgeable members have voiced opinions and many were leannig toward the IP. Good calls.

Makes me start to get concerned about my IP with 307,000 miles on it with original seals, although the previous owner of the car (since new) did not run biodiesel or grease.

swanjp26 said:

No, actually.. It looked pretty good.. Everything past that hole was drastically cleaner. possibly bc it's always submerged in fuel? As it leaked, the fuel level in the pump would drop leaving fuel to dry out on the upper components leaving this residue behind.. maybe? It almost has a fiber like consistancy. Maybe that grade-A B100 was eating up fuel filter media lol. Nasty stuff.

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How is this possible with biodiesel? I don't get your assumptions. Eating fuel filter media?

Dirty, unfiltered fuel would seem more the case.

jokila said:

How is this possible with biodiesel? I don't get your assumptions. Eating fuel filter media?
Dirty, unfiltered fuel would seem more the case.

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I am only guessing at the cause of build up in there. It looks much worse than normal for a 200k engine tho, and the previous owner was running biodiesel that him and his buddies where brewing up. Could have just been a neglected filter I have no idea really.

Is my air flow actual being 200 higher than specified, all the way through the RPM range (in neutral) anything to be concerned about?

swanjp26 said:

Is my air flow actual being 200 higher than specified, all the way through the RPM range (in neutral) anything to be concerned about?

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Double check the PN on your MAF. ALH and BEW MAF's report different values at idle. IDPARTS has the correct PN listed...

ALH: 038906461C
BEW: 038906461B

swanjp26 said:

I am only guessing at the cause of build up in there. It looks much worse than normal for a 200k engine tho, and the previous owner was running biodiesel that him and his buddies where brewing up. Could have just been a neglected filter I have no idea really.

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Thanks for setting the record straight.

Running straight, yet partially filtered waste veggie oil is one thing because it's still "dirty", but biodiesel would have been typically filtered and cleaned up during the transesterification part of making bio. It's not dirty. If anything, the properties of bio tends to "scrub" your tank off all sorts of crap living in the diesel environment. It will release the particles and they float in the fuel. So much so when some people start using bio, their fuel filter can plug up with the stuff.

Maybe they bypassed the fuel filter for a time because that event happened giving a nice bed for the stuff to attach to. Over time it just caused your situation to happen. Was the stuff kind of waxy in a way?

Turbo seals went bad have a little oil in the intercooler, what's the best way to clean this out? I have confirmed the turbo seals did go bad. What else should I do since his happend. The car would idle no problem but as soon as you would give it gas it would try to go into run away but I cut ignition and let it die. What else should I do here I already have a new turbo and all new gaskets what other preventative measures should I do before turning it over again?

Maybe start your own thread. It'll get more responses. It would also help to know if you have a New Beetle or a Jetta.