Long crank/lots of white smoke - VCDS data

About a week ago the Jetta started taking an extended crank time and puffing out lots of white smoke that smelled a bit like diesel. The engine would run quite rough, shake the car as I have the ECS dogbone mount, for almost a minute. Once warmed up things seem to be fine until giving the car heavy throttle and rpms are above 3400. Power just stops and will not rev.

I have unplugged the CTS sensor for full glow plug time and that changed nothing. The fuel filter and thermostatic tee are new. The injection pump a new unit about 12k miles ago. The timing belt was done by a reputable shop 12K miles ago. The car has 162k miles and before I purchased the car 15k miles ago the unkown previous owner had run WVO in the car (unkown length of time it was used).

The Vag-Com pulled a code P0252 that came on the other morning when it was 40* and the car stalled twice upon starting and running for a few seconds.

Here is the data I captured on VCDS:





I am thinking a leaky injector and some diesel purging is in order. What do you GURU's think?

I just got the Vag-com and am learning to use it. Let me know if you need anything else.

Travis

Upon further looking the code appears to be a P1248 - 35-10 -Control deviation intermittent.

This is a long shot, but try unpluging the MAF sensor and start your engine. If it cranks replace the MAF.

I did forget to add that the MAF is a brand new OEM unit, I also cleaned the harness connector and filled it with dialectric grease. I will try unplugging it and see what that does. The battery is also a brand new unit.

Looks like timing is pretty retarded. Would make cold starts pretty difficult, and kill high RPM power.

Is this problem progressively getting worse? Does the white smoke clear as soon as the egr valve opens?

Can you read the Fuel Temp Sensor?
I too had this problem with my old 02 Golf, replaced it and adjusted the timing mechanically, cleaned the inside of the pump while I was in there as well


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The problem has just gotten much worse. I did a can of diesel purge earlier today and that did nothing to help the problem. The car sat after a 20mi drive for 6hrs and then would not start after a lot of cranking. Unplugged the MAF and that had no affect. Continued cranking for 3 more extended periods while fluctuating between full throttle. Finally started and ran rough. Drove 20mi and shut car off for 5minutes. The car would almost not start again. Parked for the night.

I can read the fuel temp. Read earlier today when cold to check between the intake/CTS/Fuel for accuracy. Was within 2* of the CTS.

The white smoke clears as soon as the car begins to warm up.

I also cleaned the harness connector and filled it with dialectric grease.

Click to expand...

Start by cleaning out that non-conductive dielectric grease from the MAF connector.

Actually, start by getting some readings of the MAF requested/actual of a full throttle run up hill in third gear. Then clean it and do the same run.

I know this might sound crazy but next time you go to cold start it remove the oil cap. Just ruling out a plugged ccv puck. After that I would make sure the maf is reading correctly.

Group 13(cylinder balance) is not looking so healthy. Something is up with #3 cylinder. Your idle IQ is a bit high too.

Go to group 000, hit go, hit basic settings, and then hit TDI timing. Select ALH from the drop down menu and see where the graph is sitting. It should be between the mid and upper line.

What is the history with the timing belt?

Thank you all for your help. Timing belt was done at Continental Imports in Gainesville, FL roughly 15k miles ago with the injection pump/in tank pump. At the same time the head was removed to clean the abundance of carbon buildup as well as the intake cleaned. The CCV puck was replaced with new OEM unit about a week ago.

Yesterday after my diesel purge I parked the car and it would not start. Tried again this morning and nothing. Lots of spinning over but not trying to kill the starter. If I hold full throttle it will spin over faster and almost start. I didn't want to push it.

What is my next step? Very frustrated. Having to ride my motorcycle in this cold weather. I am going to check the in tank pump for operation now and do a compression test cold I suppose.

Just a wild shot in the dark. You said it is cold. Are the glow plugs working?

It's 70 out now. Does the same thing no matter what temperature.

Got it to start and stay running after much cranking and stalling out immediately which was accompanied by clouds of smoke that smelled of diesel (70* out). Going to warm it up and check the timing in VCDS. Will post results. I will do the compression test after it is warmed up as well.

Well it has gotten weirder. Once warmed up the engine started hunting for idle drastically from 798rpm to 1008rpm. The glow plug light would start blinking and it would smooth out a bit then it would go off and continue hunting for idle. Never done this before. Below are the graphs I captured including timing which is not good.

Car will not start back up now. Period.

Compression checked out good (engine warm):
Cyl. 1 - 518
Cyl. 2 - 505
Cyl. 3 - 510
Cyl. 4 - 500

Shop fubared your car. Timing is wayyyy off.

Group 13 still looks bad too. I think you have several issues going on.

I gather what you are saying but the timing job was done almost 13k miles ago. Car ran good when I bought it from the used car dealer. Found out it was in limp mode caused by the MAF. Replaced that and then the car was perfect, lots of power, ran smooth for many thousands of miles. Then all of a sudden within a couple weeks it started hard starting/smoking/and then the latest no start/idle hunting.

Any ideas what I can do next besides taking to a shop here in town?

I think you got a couple of things going on here.

First, the timing is WAY off. Best guess - the bolts holding the sprocket were improperly torqued and it has slipped.

I would pull the timing cover and make a good, detailed inspection for anything being amiss. Assuming everything looks ok carefully inspect the injection pump sprocket around the bolt slots for evidence that it has slipped (or worse, obviously loose bolt(s)!)

Step 1, assuming everything under the timing cover looks ok, is to reset the timing; you're far enough off the bottom that you have to correct this. Note that the solenoid is at full actuation trying to keep the SOI in the window and is failing to do so; your injection at idle is out-of-spec late. With injection happening beyond TDC I'm not surprised it runs like crap and/or refuses to start. To advance the timing the three sprocket bolts are loosened and then the center nut is rotated FORWARD (clockwise) a small amount (small = just perceptible movement of the bolts in the slots.) Then tighten the bolts back up (18ft/lbs) and see where you are. A small advance should get you into the window where the ECU can get injection into the window. If the bolts are BLUE in color STOP -- you have the old stretch bolts and need to get the current replacements before doing this. This should not be the case as you state the timing belt has been changed.

See if the car will then start and run. The other problem appears to be two bad injectors (idle balance is quite far out.)

It's POSSIBLE you've got a bad pump, but checking the timing for slippage (it should visible if the sprocket moved) is free and if you fix that and the car now starts but still runs like crap and the injector balance remains way off then I'd have the injectors tested -- that's reasonable in cost. A pump is expensive so work the process of elimination here.

White smoke is also to be expected with late injection as not all the fuel burns.

If your IP bolts are tight and the timing belt tensioner is tight, I would look to a loose crank sprocket. One that is drifting will cause the same symptoms, but Genesis is right in that I think you have more than one problem. Confirming the static timing will reveal the problem and it's easy to do. Forget the work the garage did, everyone can make mistakes and things happen.

Yeah, I'd probably pull the valve cover and vacuum pump and check the cam/crank/pump timing, especially if I didn't see evidence of the IP sprocket slipping on inspection. Let's hope you didn't lose index on the crank or cam; those are bad news -- the IP losing reference doesn't cause valve collisions.

But if it's still on the graph and running, albeit poorly, then I doubt it's gotten to the point of piston contact...yet.

Probably. And that makes for a good reason to check the crank and cam timing relationship so you know it's intact, so point taken.

Thank you Genesis and Abacus. I pulled the timing cover off and checked everything. It does appear that the three bolts have slipped. I place a short wrench on them and it was easy to break them loose. I did not adjust the pump as I ran out of good light and my neighbor came by all chatty. Pictures of what I found below.

That upper idler roller looks pretty old. Do me a favor and using a small mirror, tell me what the date code on the tensioner says. This is what it will look like, keep in mind it'll be through a mirror.



And here is a closeup of it.




And here's what it will look like in the mirror:




The reason I'm asking is because that idler roller looks older than 12K, so I'm wondering if they did the last timing belt job correctly. Those should have been replaced with the last belt, and the first two numbers of the date code are the week of the year and the last two are the year, so in the picture above, the tensioner was manufactured in the 50th week of 1995 (so the last TWO timing belts were done incorrectly since the car had 137K on it, and one was by a dealership). I have seen new tensioners, from reputable vendors, that are almost 2 years old, but if it predates that, I'd bet it wasn't replaced with the last timing belt job like it should have been.

Just something to check. I wouldn't want you to have a timing belt mishap in short order and have it ruin your engine.

Definately looks like a bad timing belt job is contributing to your issue. My top roller has almost twice the mileage on it and looks like it did when it was new. Your IP sprocket bolts look like they were reused. Also looks like you have paint marks on the timing belt cover above the cam and ip sprockets.

I would start by getting it retimed and then consider having the belt and rollers changed again properly.

I would get new bolts to change the ones that are holding the pulley on the injection pump. Then take them out one at a time a snug them up. Then loosen them all and using a 23 mm wrench tweak with the wrench going towards the front of the car until you sense movement. Tighten the 3 13 mm bolts to IIRC 18 ft-lbs, recheck the timing.

As you are on the graph it will not take much to get it to the middle.