ALH TDI VE injection pump quantity adjuster test?

Hi All,
I've been working for weeks to troubleshoot why my 2002 VW Jetta TDI cranks but won't fire. The injection pump does not release fuel. The only code I repeatedly get is 00849 indicating a bad connection on the s terminal ignition wire circuit. I've checked the ignition switch and done everything else I've found possibly related and everything checks out. I verified fuel supply to the pump, changed filter, replace relay 109 & verified cutoff solenoid has 12 volts before and during cranking. When I watch the quantity adjuster with the injection pump cover removed it only moves about 20 degrees clockwise when key is turned on stays there while engine is cranking then closes back counterclockwise when key is turned off.

The only other troubleshooting I've done with vcds is observe all fuel or injection quantity and timing blocks while cranking and they all indicate zero flow. Can anyone confirm whether my issue is mechanical injection pump related or more likely electrical? can error code 00849 create a no-start condition by the ECU perverting the pump from releasing fuel?

The background story that might help is that the initial issue was a collapsed vacuum line which prevented the turbo from engaging and made the engine very sluggish and probably overheated the turbo section. After replacing vacuum lines d engine idled and revved up fine on the lift for a minute but after I shut it the crank and no start condition began.

I don't see an option to attach my auto scan results so any suggestions there might also help. Thanks!

Cory.Miller said:

I don't see an option to attach my auto scan results so any suggestions there might also help. Thanks!

Click to expand...

Please paste it in-line, preferably between CODE tags, as shown here.

-Uwe-

OP:
Calm down and post the scan as Uwe instructed!
Does engine run with starting fluid?
Did you verify you didn't cross the wires for PCV element with solenoid for the anti shutter flap in front of EGR valve or a vacuum line causing the valve to remain shut during engine operation attempts?
Basics first, now JPPSG!

Thanks Uwe and Jack. Here's my scan. I'll post my measured fuel data next.
I have verified that my ASV isn't closing during cranking. It doesn't move at all during key on, crank or key off. Should it?
Yes it does fire when it is given a shot of diesel safe starting fluid. I can get it to fire if I crank for 5 seconds while holding the pedal to the floor, but it on fires a couple time with lots of smoke. I assume this is just lighting off the little bit of fuel that is getting through the pump.

Here is a scan results taken just now. Oddly enough, code "00849 - S-contact at Ignition/Starter Switch (D) 25-00 - Unknown Switch Condition" is not there which is new tonight after 3 weeks of this being the only code that is always there. I think because code "01330 - Central Control Module for Central Convenience (J393) 49-00 - No Communications" just appeared after I removed and replaced relay 377 to check for burnt terminals. I replaced relay 109 after blowing it out during testing of the solenoid. It seems like lots of engine cranking without firing is causing relay failures. I also don't know why the last code "01331 - Door Control Module; Driver Side (J386) 49-10 - No Communications - Intermittent" won't go away after I just unplugged it while inspecting wires behind door panel and in door hinge. I guess I blew another relay while testing. I'll replace it tomorrow and see if I get back to the previous status of only seeing code 00849. ....I'll remain calm Jack... good advice! I'm excited to get this old girl running right again, then upgrade to my Audi Quatro and start learning what quirks it has.

I'm wondering if your unsanctioned welding damaged the engine controller?
I would try ignition switch & FYI you should not be burning up relays by testing them, if you are you need to take time to learn more about how to test stuff before commencing further.

I'm more concerned that the ASV is open during the engine actually cranked because when the vacuum pump initiates if wired or routed wrong or faulty, it will close the flap with vacuum created.

Hi Jack,
Yesterday I found a broken white wire in the driver door and fixed that. Then the related codes to the convenience control went away and the 00849 code came back and is the only one that could be related to engine not starting. I verified the engine starts easily with starting fluid. I noticed if I hold the pedal to the floor the engine will stay running longer. I did think the fuel quantity adjuster is being told by the ECU not to open. I think I need to find the wire diagram to trace the S contact wire from the ignition switch though the CCM and to the ECU. Thoughts?

Hi Jack,
Yesterday I found a broken white wire in the driver door and fixed that. Then the related codes to the convenience control went away and the 00849 code came back and is the only one that could be related to engine not starting. I verified the engine starts easily with starting fluid. I noticed if I hold the pedal to the floor the engine will stay running longer. I did think the fuel quantity adjuster is being told by the ECU not to open. I think I need to find the wire diagram to trace the S contact wire from the ignition switch though the CCM and to the ECU. Thoughts?

Click to expand...

Okay that means crank, and cam are in sync but pump is TBD and since it runs we can assume that exhaust and intake are clear to permit air.


Okay did you do the following?

Trace all wiring to all ECU tracks by load light test & isolated?

Ohm out all respective sensors and verify there function as per the RTFB?

Verify mechanical's for timing of pump & that fuel is making way from tank to fuel filter & then to pump and that plunger in pump under solenoid actually lifts & to permit fuel flow to HPP of injector distribution and to fuel timing barrel commencement valve?

You have no DTC's for pump so i'm speculating a fuel starvation or air bound issue maybe compounded by faulty air leak at fuel filter or pump return, have you sucked fuel with mighty vac & at return side of pump lines to see if fuel is primed and will hold a static?

The aforementioned mighty vac test, will qualify the pump and fuel filter for seal back to tank.

Hi Jack, Thanks for the continued support. Here are my answers to each of your questions:

Trace all wiring to all ECU tracks by load light test & isolated?
I think this is the best next step once I find the wiring manuals. I'm still trying to get the wipers off so I can get to the ECU. I'm letting creep work it's way through the rust.
I found the Bently manual online, but it doesn't have the wiring diagrams. Can you let me know where to find these?

Ohm out all respective sensors and verify there function as per the RTFB?
Yes, I will do this too once I get the wiring diagrams and methodically verify each system.
Do you think the CCM is a potential failure point? If so how would I test this?

Verify mechanical's for timing of pump & that fuel is making way from tank to fuel filter & then to pump and that plunger in pump under solenoid actually lifts & to permit fuel flow to HPP of injector distribution and to fuel timing barrel commencement valve?
I don't know how pump timing could change if the rest of the engine is still in time so I haven't checked this. If it's possible that the pump lost timing, wouldn't that mean there is a bigger issue with the pump which could be verified other ways?
I'm not sure how to verify if the solenoid actually lifts the plunger when switched on. I replaced the solenoid and relay 109. I think I put the plunger and spring in the correct way, but I remember thinking that it's weird that they just kind of sit in there loosely. Any suggestions on how to verify this?

You have no DTC's for pump so i'm speculating a fuel starvation or air bound issue maybe compounded by faulty air leak at fuel filter or pump return, have you sucked fuel with mighty vac & at return side of pump lines to see if fuel is primed and will hold a static?
I used a hand vacuum pump to verify fuel flows freely to the HPP. I then tried pulling fuel through the HPP from the HPP return line fitting. After several tries and holding a strong vacuum for a while and cranking the engine still no fuel or air flow coming through the pump. I just found this thread and now think it's likely that my HPP is toast.
https://forums.tdiclub.com/showthread.php?t=281400
What part in the pump is likely failed in this case?
If it proves that my pump is toast, then is it possible that my error code 00849 is a not related? Or even if I replace my pump, will the code 00849 still prevent the HPP from releasing fuel?

If it's the pump, where do you recommend buying a refurbished one?

I read that the fuel release valve could be the cause for fuel pump not flowing fuel through. I removed it and broke the valve in half in the process. Maybe the fuel release valve was stuck causing it to break below the threads during removal? With the bottom half check valve portion removed and the to replaced to seal the cavity, I primed the pump again and tried starting. It got enough fuel to fire but not enough to stay running. Maybe the new release valve will work. Or maybe the pump is vapor locked? I read about this happening to the high pressure gear part of the pump. Thoughts?

After replacing the pump case pressure relief valve, then priming the fuel lines, then cranking and not starting, I found the case pressure relief valve broken again. At this point I called Huckstorf diesel which have been helpful in fixing my duramax in the past. They said the pump must have a mechanical failure inside given all the troubleshooting results so far. I pulled the pump just before flying to Toledo to drive my new 2014 Audi A6 TDI home.... short term transportation issue solved. I love this car! I’ll have read more about ECU tuning and the risk of loosing the warranty before playing with that more.

....back to this poor old Jetta TDI.... I think I will tear down the pump myself with the hopes of finding a broken return spring which I’m told is the one possible failure that can be fixed without a full pump rebuild. After the new timing belt kit and resetting the pump quantity adjuster, I might fix this thing. I’ll let you all know how this turns out.... until then.... A6 TDI!!! ....by the way there are some awesome deals out there for the last of the TDIs VW will likely sell to the USA..... thanks EPA for killing the future of TDI engines in America which could have done more to reduce total emissions in the long term. Yes VW did a bad thing, but in my opinion the EPA and CARP over reacted on this one. Cheers to the engineers and all people of VW and Bosch that produce these brilliant cars. Ich liebe VW!

Cory.Miller said:

I’ll have read more about ECU tuning and the risk of loosing the warranty before playing with that more.

Click to expand...

I wouldn't. If it's been "fixed", it's got an awesome warranty on all the complicated and expensive emissions stuff. But the problem with "fixing" them is that the fix is hard on all that complicated and expensive emissions stuff, and you'll likely need that warranty.

We have a 2015 Touareg with what's essentially the same engine as your A6. We've had it since new and I'm really torn as to whether I should allow it to get "fixed". We've got until the end of the year to decide...

-Uwe-

Here's an update for anyone still following this....
the Bosch VE injection pump is taken apart and I have confirmed than in the high pressure section there are no obvious mechanical failures or wear. After much additional research including finally finding the pump operation manual, I'm certain I understand the details of the pump's functional requirements and am left with the follow conclusions:
1. The broken case pressure relief valve (aka pressure control valve) seems like the most likely culprit to my crank-no start issue. Since this issue developed suddenly and didn't get progressively worse like many instances I've read, it seems plausible that this valve "let loose" in a more extreme way than normal (press collar full drop) which created the instantaneous no start condition. The jammed collar resulted in a seizing the lower half of the case pressure relief valve which caused it to break in half during removal. The break in half caused the removal to slightly damage the threads which led to an crooked installation of the new valve and caused the second one to break. I'm hoping that the next valve I install very carefully will solve the problem.

2. I do wonder if the "overflow restriction valve" in the fuel return fitting at the top of the pump could prevent enough fuel flow for engine start if the valve is plugged. without have a pressure drop spec, I cant test it, but it seems pretty restricted when I try to blow through either end. When reading that case pressure of around 30 psi should be maintained while flowing sufficient fuel through this valve back to tank, it seems plausible that the tiny orifice could be mostly plugged which could mostly dead head the low pressure side of the pump and thus starve the high pressure side. I'm debating if I should buy one now to eliminate this possibility, but I think I will wait and try conclusion 1 above first as to not change 2 things at once. Thoughts on this theory would be helpful.

3. I've read that the start of injection timing solenoid failure can cause what I observed just before the engine died and wouldn't start anymore (without starting fluid). It ran rough and smoked. After much reading on forums about this and reading pages 54 - 57 of the Bosch VE pump operation manual linked above, it seems possible that this solenoid could fail to open (normally open) which causes the injection timing to be fully retarded which seems like it would make the engine run rough and produce lots of white smoke with the injection being too delayed. But I don't think failure of this solenoid valve by itself would cause my no start issue. Plus, if it were failed I should be getting a couple of related engine codes. Since I can't verify operation of this valve without using a full can of starting fluid to run the engine while logging vag-com start of injection graph, I can only check resistance through it which is between the 10 - 20 ohm range I read is expected. So I don't think this solenoid valve is bad (good thing since it's about $300).

3. The fuel quantity valve seems to move freely and since I verified it moves to the mid range of control when the key is tuned on, I expect this is functioning normally.

4. After reading in the manual (linked above) about the "delivery valve" inside each of the high pressure injection line fittings in the high pressure pump body, I don't think these could be the problem. They are basically a check valve designed to open at a certain high pressure when given each burst of fuel per ignition event, then close to keep the high pressure fuel line at case pressure until the next injection pulse.

So without further input, I'll be putting this pump back in, changing timing belt water pump and pulleys while in there, then putting the new case pressure relieve valve in when it arrives later next week and giving it a try. I can't wait to get this thing solved so I can focus on upgrades to my Audi A6 TDI! Thanks all for the input.

Post Pictures............. or it never happened!

To close this thread.... I had a bad quantity adjuster on the injection pump. I found a working pump in a scrap car and after putting that pump in along with timing belt and water pump, the car fired right up. I have worked on and off for the past 2 months to figure out why the car now smokes badly and doesn't have power. My mighty vac showed the wastegate was sticky. After removing and cleaning EGR and turbo hot section, then reassembling, the car runs better (boos control working). Now my issue seems to be too much EGR. At idle is smokes a lot and after 2 minutes when the EGR closes, the car runs better, but still doesn't make power (boost actual lower than boost requested). I tried putting a block off plate before the EGR cooler which resulted in the car idling great and revving smooth at idle, but when driving, it would through the overboost code before shifting into 2nd and going into limp mode. VCDS confirmed the over boost with EGR blocked and underboost with EGR setup normally. I did set EGR value to minimum of 33768 which didn't seem to change anything. Mass airflow actual reads lower then requested when EGR is unblocked, but actual reads higher than requested when EGR is blocked. I tried a new Bosch MAF sensor which didn't change anything. I've verified no air leaks in the EGR/boost system or vacuum leaks in the EGR/Boost solenoids Both solenoids appear to cycle properly by VCDS.

I will create a new thread with a related subject. When I do, I'll post the Autoscan and data logged with the relevant measuring blocks.

FOD and maybe induced........

Did you recheck work steps?