2.5 years broken, new head and having issues getting it going again

long story short 2003 jetta auto alh
stage 1 tune years ago, muffler delete, egr delete
2.5 years ago water pump locked up and shredded timing belt.
Last week it got a new cylinder head and timing job.

Now runs poorly and will not get out of its own way half the time, the other half it can run on the highway just no hills or it gets slow..
Having p0102 and low glow plug circuit code

swapped MAF, cleaned grounds under battery terminal and block, new air filter, liquid moly diesel cleaner run straight to pump, removed the screen in pipe by air filter, cleaned the other maf with spray,
another mechanic checked injector flow and everything with VCDS and said it did not read any maf or map sensor reading at the time.

Sometimes you drive it and it feels like 40hp and it will not accelerate up a hill, unplug maf and it feels like 60hp and will make it up a hill and rocket down a hill.. Sometimes it drives ok with maf plugged in, if you turn it off going down the road and turn back on, sometimes it drives very poorly until CEL comes back on

My scanner at idle reads 28.5 in hg on map and 0.0 lb/ft maf also ect 100* when its closer to 190*
It feels like its rich but runs poorly, how can a diesel be rich and run poorly? If i stick my hand over the intake tube it chokes it out easily letting me think there isn't a huge air leak post maf? Turbo sounds good and spools up and sounds like it releases boost letting off throttle. not just a whoosh of air, no apparent boost leaks we have found or believe there could be

After driving a few days, headlight low beams only work on parking lights and high beams are a must with headlights on..

heater doesnt respond well, maybe blocked up heater core?

Any help? thanks. I do have a vagcom cord but no VCDS.. willing to get if needed, just havent used it myself

You definitely need to download vcds and plug that cord in.
To things that jump out, besides sitting fuel, are the MAF and Map sensor readings alone with the erroneous temp readings. Might need to replace the map and temp sensors...

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The wiring leading to the MAF sensor, my daughter has an issue with hers, I cleaned the connector and checked the wiring and put some electrical grease in the connector. Not di-electric but the stuff that’s supposed to enhance electrical connections. A little pack at autozone was less than $2 but I had to ask at the counter for it.

As these cars age more and more weird problems will start popping up.

What codes are you getting?

eddieleephd said:

You definitely need to download vcds and plug that cord in.
To things that jump out, besides sitting fuel, are the MAF and Map sensor readings alone with the erroneous temp readings. Might need to replace the map and temp sensors...

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Click to expand...

VCDS paid only or the free be ok? I will go start that now with the laptop at the shop

Tdijarhead said:

The wiring leading to the MAF sensor, my daughter has an issue with hers, I cleaned the connector and checked the wiring and put some electrical grease in the connector. Not di-electric but the stuff that’s supposed to enhance electrical connections. A little pack at autozone was less than $2 but I had to ask at the counter for it.

As these cars age more and more weird problems will start popping up.

What codes are you getting?

Click to expand...

I have tried to clean with battery corrosion stuff, and the spray for electrical contacts.. Maybe bad wiring harness but the plug looks like new inside and wires all seem fine? its been off 20+ times trying to diagnose
Wont hurt to try the grease, ill stop by autozone on the way to work.

I will volt test everything as well

You said you have a cable.
If it's a RossTech cable the software is free, download the fill version.

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I'll bet $2 on sticky turbo veins/turbo issue, but make sure your timing is in check as well.

I’d bet $2 on that too.

ok I just hooked up my cable and got the lite version, figuring it out.
1st:
I looked at voltage on maf wiring and i had battery voltage and 5v, the ground didnt show continuity with the battery and the 4th wire had resistance but no voltage

VCDS:
no matter what the maf is 550
idle-
group 13 iq is 0.0 -0.19 0.0 0.21
coolant temp is correct in VCDS

looking at commanded boost vs actual boost they are close in numbers which was max 2160mbar, 2.1 psi.. sad
It sounds like its building boost and when it had a boost leak it still rushed air very loudly from the pipe..
Shop checked boost leaks again but i havent? worth a go i guess to see if maybe, but if not the Turbo is sticking causing low boost?

ok, so i logged and tried to use multimeter to get the MAF to work.. there was spots on the log that went from 550 to 0 to 1275, but no other three numbers
grounds are all good, voltage is 0.1v at idle coming off maf to ecu

VNT questions..... apply vacuum or pressure to test actuator and sould i try and force to stay open or force closed? anyways the vnt actuator can be manipulated to test?

Vacuum pump and open it all the way. Watch to see it opens smoothly and remains open showing it'll hold vacuum.

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When using a vacuum pump to move the vent actuator you want to see that it starts to move at around 5 inches of vacuum and be fully open by 18 inches and be hitting the stop.
As stated above it should move smoothly and not be erratic , it should also hold the vacuum and not leak down.

It did feel a little stiff at first and I did not have an adapter to put my vacuum gauge on it so I did it by mouth and hand to wiggle. It did feel a little loose maybe??

I just got engine degreaser gel from the parts store and a thing of oven cleaner from Dollar general.
My EGR was blocked off near the intake inlet. But I removed the EGR tube go into the cooler and sprayed two bottles of engine degreaser and oven cleaner down that tube and has the phone was expanding I put the EGR block off plate on that spot instead of after the cooler like I had it before. So now my cooler has no exhaust flowing through it anymore but I still have it there for the coolant to flow.

So hopefully after doing the degreaser to the turbo it can unstick the veins. Maybe!!!

All the vacuum lines look like crap but they did all work and hold vacuum even the actuator held vacuum perfectly..

I just finished it up a minute ago is been sitting for an hour and some change now and I have it all put back together. I started the engine up and let it run for a few minutes until a little smoke is coming out of the exhaust at that point new to the turbo is getting hot and the degreaser and cleaner was too.. so every 10 minutes I started up and let it run for a couple minutes just to keep the turbo hot and every time after it runs for a couple minutes it starts to pour out smoke. Going to do a couple cycles like this and then go for a drive.

Maybe it felt a little better on the drive... But not what I had hoped still cannot get to 40 by the end of the onramp
It is still very intermittent on the way it acts, but a few pulls did better than i think it would have before..
Would this video be any help? That was not near as fast as you would think.. first part was 5-8mph and the other was maybe 20-28mph
https://photos.app.goo.gl/adUtzzG3tnJtUJc66

Tonight:
25$ Amazon MAF
10$ Amazon fuel filter - added 1/3 can seafoam + the 1/3 can left of liquid moly diesel
30$ new vacuum lines - removed EGR and shut off valve and only ran N75
Tested vac lines with MightyVac and the actuator started at 3inhg and was fully open around 18inhg, did that 20 times or so and it was smooth.. I did do the oven cleaner last night and moved EGR blockoff to the exhaust manifold instead of egr cooler.. But last night and today it still drove poorly

BUT Tonight the MAF code went away and it Runs Great!! Boost comes on great and pulls just like an auto ALH should

If your new MAF isn't a Bosch or Pierburg you should start saving up for one that is.

Jmanninb91 said:

Tonight:
25$ Amazon MAF
10$ Amazon fuel filter - added 1/3 can seafoam + the 1/3 can left of liquid moly diesel
30$ new vacuum lines - removed EGR and shut off valve and only ran N75
Tested vac lines with MightyVac and the actuator started at 3inhg and was fully open around 18inhg, did that 20 times or so and it was smooth.. I did do the oven cleaner last night and moved EGR blockoff to the exhaust manifold instead of egr cooler.. But last night and today it still drove poorly

BUT Tonight the MAF code went away and it Runs Great!! Boost comes on great and pulls just like an auto ALH should

Click to expand...

If the MAF was $25, you need to realize that it may work for a while, day, week, month and then your'e going to be back at square one. You'll need to get a Bosch to fix it right.


Glad you found your problem though.

Tdijarhead said:

If the MAF was $25, you need to realize that it may work for a while, day, week, month and then your'e going to be back at square one. You'll need to get a Bosch to fix it right.


Glad you found your problem though.

Click to expand...

For sure! MAF plugged or unplugged gave default reading on vagcom.. It ran horribly and my mind is blown how much it effects it.. I didn't want to buy a 160$ maf if it didn't fix it. Was worth it in my opinion

Not quite $160, but I understand your thinking.


https://www.idparts.com/bosch-mass-airflow-sensor-maf-a4-alh-p-242.html

Tdijarhead said:

Not quite $160, but I understand your thinking.


https://www.idparts.com/bosch-mass-airflow-sensor-maf-a4-alh-p-242.html

Click to expand...

Nice, i was going of advance auto price.. I will test how long this will last for everyone lol... Have some electric grease in the garage im going to add just to do it.
But its running great! I am so happy to have my diesel back, cold starts are really smokey and has a misfire for first few seconds..
Any help with that? Going to start researching now. I have a new glow plug harness I got years ago when i did the glow plugs but didnt change it. going to do that eventually

I would seriously find a Tdi guru or a member on here who has experience to maybe help you out for a fee , maybe a case of beer, etc.....

I would like to see where your IQ is set at too.

I personally would like to see the mechanical timing is set correctly......not close, not a tooth off but correct.
Then I would like to have Vcds hooked up and set the timing between the middle and the upper line.
All 5 of my cars are set up that way and no issues whatsoever ever on starts.....even down to 0f degrees.....

csstevej said:

I would seriously find a Tdi guru or a member on here who has experience to maybe help you out for a fee , maybe a case of beer, etc.....

I would like to see where your IQ is set at too.

I personally would like to see the mechanical timing is set correctly......not close, not a tooth off but correct.
Then I would like to have Vcds hooked up and set the timing between the middle and the upper line.
All 5 of my cars are set up that way and no issues whatsoever ever on starts.....even down to 0f degrees.....

Click to expand...

Thanks for the reply, I got vcds and ready to play with it soon to check iq and adjust. It puffs a decent bit of smoke on start-up and during boost you can see a little in the rear view little

I think they all blow smoke on start up. The little bit you see in the mirror at boost could be a loose or leaking boost hose. Either a plastic one with a crack/split or a rubber one with a hole/split or it’s not seated correctly.

Or the cheap MAF may not be entirely up to the task.

A diesel purge might help both those issues and the rough start misfire.

Let us know where the timing and IQ are set.

Tdijarhead said:

I think they all blow smoke on start up. The little bit you see in the mirror at boost could be a loose or leaking boost hose. Either a plastic one with a crack/split or a rubber one with a hole/split or it’s not seated correctly.

Or the cheap MAF may not be entirely up to the task.

A diesel purge might help both those issues and the rough start misfire.

Let us know where the timing and IQ are set.

Click to expand...

Timing was right on the bottom line in vcds, within spec but retarded
I did a diesel purge and new fuel filter recently with a seafoam partly filled fuel filter after diesel purge.

I adjust the idle lower and its smoother, the trans is whining at idle so i assume low trans fluid.. Going to do a fluid and filter change. 3 years ago a roomba harness and reman valve body was installed.


everything was running within spec it looked. First time using vcds still tho.

https://photos.app.goo.gl/Q4R89eBUcv7dkXW7A

Jmanninb91 said:

Timing was right on the bottom line in vcds, within spec but retarded
I did a diesel purge and new fuel filter recently with a seafoam partly filled fuel filter after diesel purge.
I adjust the idle lower and its smoother, the trans is whining at idle so i assume low trans fluid.. Going to do a fluid and filter change. 3 years ago a roomba harness and reman valve body was installed.
everything was running within spec it looked. First time using vcds still tho.

Click to expand...

I would move the timing to near the top line, also let the car fully warm up before setting the timing.

Tdijarhead said:

I would move the timing to near the top line, also let the car fully warm up before setting the timing.

Click to expand...

Adjusting the gear on the injection pump? Right.
From at the bottom line to at the top line is a pretty big difference?

Actually if you're in the window you will be fine, the ECU takes over. But most of us set it to the upper range. I've read optimal is right in the middle, then advance it slightly with VCDS basic settings. Be careful.

It only takes a very small movement on the IP nut , forward to make a huge difference, we are talking like 1/32 to 1/16 of an inch. Like a nit on a nats nut small.

csstevej said:

It only takes a very small movement on the IP nut , forward to make a huge difference, we are talking like 1/32 to 1/16 of an inch. Like a nit on a nats nut small.

Click to expand...

Awesome! I tried to adjust in vcds but it still didn't adjust when I went back to the timing chart. Adjusted trans to shift better and it helped. Also iq from 2 to 4?
Haven't done timing but starts seem little smoother less smoky.
But!! Timing adjustment will be ASAP

IQ moving from 2 to 4 or 4.5 will reduce some of the smoke. Both my daughters cars are set at about 4.5. Their timing is set to just below the top line. As Steve said a tiny movement of that central nut makes a big difference.