Power loss in first gear under moderate to hard acceleration. Help...

I have a 2003 Golf with Bosio 520 injectors, ported and polished head, stage II cam, VNT-17 turbo, and Kerma tuning. I recently put the new head on with the new cam and lifters because the head gasket let go. I also did ARP studs and a few other odds and ends. Car ran great for a couple of days, then it started having issues in first gear and only first gear. If I apply more than half throttle the car will lurch at about 2700 RPM, followed by a huge cloud of black smoke and then near zero power, the engine begins to chug loudly and at times it even dies. It eventually clears up and I’m off again. Car does fine in every other gear... I’m lost... I looked at vacuum lines, seems everything is in order. I did see an 3/4 inch bubble float through the fuel line when I had the hood up, made me think air, but it’s just strange it’s only in first gear. It also takes a sec to start when it’s cold, and runs rough for a few seconds. It didn’t do this before the head swap and stage II cam. The first time it happened I immediately thought it’d jumped a tooth on the timing belt so I shut the car off and inspected the belt, belt is tight and no teeth are missing. So I’m at a loss, could the timing be slightly retarded? So far I can’t find any answers, I found a thread that matched this but the owner had a 2004 car. I am not sure where to begin. I installed the head myself and I’m mechanically inclined, but I am not super familiar with this particular car. I got it to drive daily and have fun with... So far it’s blown a head gasket, left me stranded, tried to overheat... The list goes on and on. On another note cylinders and pistons looked great when I removed the old head and cylinder walls still had the hash marks. So internally it’s clean.

You mentioned overheat... Did you check the block deck for flatness? Black smoke typically means over fuelling, but with your setup it *should* be OK. Have you checked your dynamic timing? How is it? What's your IQ set at? Just a few starting points.

It over heated before the head gasket swap, block is good. I’m not sure the difference between dynamic and static timing, are you talking about with the car running? Do you use a timing light like you would on an old gas engine? As far as IQ are you talking about fuel pump timing? The locking tool went into the cam the pump locking tool went into the pump and the flywheel timing mark was lined up.

Sorry for the ignorance, I’m new to the VW diesel scene.

You're in the market for VCDS sounds like!
http://www.ross-tech.com/vag-scope/TDIGraph.html
EDIT: I should mention that's it's not considered possible to properly set engine timing without VCDS.
There's physical (cam lock, IP lock, flywheel mark) and 'dynamic': ala VCDS. You need to do both.

I didn’t move the pump sprocket, it’s in the position it was in when I started this project. It ran great set where it’s at (minus the head gasket) prior to the new head and cam. Would a stage II cam and ported head really cause a change that would necessitate adjusting pump timing?

Would a stage II cam and ported head really cause a change that would necessitate adjusting pump timing?It would if the timing belt was removed. Which...it would be. It's hard to imagine the IP sprocket stayed exactly in place during all that work.
Anyway, dynamic timing is 1st on the list if you've never confirmed it for this belt.
Another helpful link:
https://www.youtube.com/watch?v=MEguZWbEE9g

Out of all the timing belts I've installed, only one was the fuel pump sprocket unchanged. All the others the fuel timing on the graph plotted off the scale. Having your fueling that off can definitely cause drivability issues. I'd start there by verifying your fuel timing.

Just noticed you're in Washington, where abouts are you? I have VCDS and can help you set it.

I am in the Tacoma area, I think it’s a couple of hours from you.

FixItDaily said:

I am in the Tacoma area, I think it’s a couple of hours from you.

Click to expand...

If you feel like making the trip just shoot me a PM

Ok, checked the dynamic timing on the injector pump, it was perfect! Go figure, I put it all back together just right I guess. The physical timing was also spot on. So I took it to a place close to base (Fort Lewis) that supposedly specializes in VW and Audi. They called to tell me exactly what I already knew. The timing is great, I couldn’t find any issues with the vacuum hoses, the fuel filter and o-ring were replaced 5k miles ago. This all started after the installation of the ported head and stage II cam. I am at a loss, could it be the MAP sensor? That was also replaced with a 3-Bar from Kerma. Could the intercooler have some oil in it or maybe water? I’m at my wits end! Thanks in advance!

It’s a brand new Colt Cam. If it was the cam wouldn’t it be an issue all of the time... Not just in 1st gear?

When you installed the 3bar map sensor, was the tune changed for it? You can't simply drop in a 3bar map sensor, the readings will be off and it'll underboost badly.

It’s tuned for it... The only thing that changed was the new ported head and the stage two colt cam.

I don't know if you have to adjust the tune for the cam, but the intake shouldn't make that much of a difference. Check with your tuner about the cam.

Talked to the tuner at Kerma, said there’s no need to retune.

Also just spent $186 at a VW/Audi shop. Guy said it was good but couldn’t tell me what they’d done. Got in the car and BAM first try car did the same thing it’s done every time. ��

FixItDaily,
I don't see anywhere in this thread where you said you got it scanned for codes. The place you took it checked timing, that's great but did they do a full scan and tell you there's no DTC's set? Also assuming your intake is clean.

2700RPM in 1st is not the same as 2700RPM in any other gear speed-wise. Could this relate to some speed sensor? Also beginning to suspect the tune. But anyway, yes it's always a good idea to ensure the intercooler is puddle-free. HTH

Guy said it was good but couldn’t tell me what they’d done.
Then what were you paying for?

For their “diagnostic”, I asked them to unplug the MAF and the tech didn’t even do that. Pretty frustrating, he said the techs tag teamed it. Whatever that means... So I’m not sure what they “tag teamed”...

Update, unplugged the MAF, symptoms were better but not totally cleared. At 4K RPM under full throttle power dips slightly followed by what sounds like pinging or like the ignition cycle is breaking up. But with the MAF unplugged it seems to pull harder. I’m starting to wonder if the tune needs tweaking.

Tag team just means more than 1 person was consulted. Unplugging the MAF is just something we'll do to see if it makes a difference, it gives a clue but is not a conclusive test. You really should query further to find out what they actually did. They may have just scanned it. Wonder if they ran any logs for data or if they even drove the car and observed the symptoms.

My only interweb guess is the turbo actuator is out of adjustment. A tune generally will not cause problems, but a tune and upgrades will exaggerate any existing issues.

I knew what they meant by tag teaming... Just seemed strange. They did drive it about 20 miles. But the guy at the counter had no clue what they’d actually done. It was 1800 and the techs were gone and I have a sneaking suspicion that the guy at the front desk isn’t extremely mechanically inclined.

I too have wondered about the actuator or the N75 valve. The actuator moves freely and that turbo is fairly new. But it very well could be out of adjustment.

You just need a vaccum pump and gauge, worst part is getting to it.
Service people seem to love those little catch phrases, they're trying to make you feel better. The guy at the desk or service writer often knows little about cars, yet they're the ones that often order the repair. For those dollars they should be able to provide you with a detailed description and list. Please call/visit back. Gotta wonder if they even noticed the slack in acceration in 1st, it's not a real common thing.

If it's pulling great in every gear but 1st, I have my doubts the actuator or N75 are out of spec.
FixItDaily, if you want a good shop to look at it, it looks like your best bet is 2 hours south of you in P-town. Rich is great to work with.
http://fixumhaus.com/
Bring him a written list of all your mods, and I bet he can diagnose it.

FixItDaily said:

Car ran great for a couple of days, then it started having issues in first gear and only first gear. If I apply more than half throttle the car will lurch at about 2700 RPM, followed by a huge cloud of black smoke and then near zero power, the engine begins to chug loudly and at times it even dies. It eventually clears up and I’m off again. Car does fine in every other gear... I’m lost...

Click to expand...

bad remaps cause pressure spikes in the exhaust manifold on spoolup
this floats the exhaust valves and the hydraulic lash adjusters pump up
you'll have valves in pistons if you do it too much

ETA: toss an exhaust manifold pressure gauge on it instead of your pyro, use a 100psi gauge, I'd bet it is spiking well over 80 psi
software solution is to reduce fuel in that area and open vane precontrol map up
hardware solution is adjusting the vane stop screw until it is laggy enough to avoid that specific set of circumstances
driver solution is to just start in second
my solution was reasonably sized turbos

[486] said:

bad remaps cause pressure spikes in the exhaust manifold on spoolup
this floats the exhaust valves and the hydraulic lash adjusters pump up
you'll have valves in pistons if you do it too much

ETA: toss an exhaust manifold pressure gauge on it instead of your pyro, use a 100psi gauge, I'd bet it is spiking well over 80 psi
software solution is to reduce fuel in that area and open vane precontrol map up
hardware solution is adjusting the vane stop screw until it is laggy enough to avoid that specific set of circumstances
driver solution is to just start in second
my solution was reasonably sized turbos

Click to expand...

So... Unugged the MAF and the problem essentially disappeared. But... After making a trip from Washington to eastern Idaho my turbo tried eating itself and was for the most part was successful. So another VNT17 (my first but it seems there are several) that experienced catastrophic failure. I’m wondering if the turbo was surging and the surging was causing the issues I experienced. I ordered a VNT17 plus, and after a vacuum test found that the N75 valve had a very slight leak. The rest of the system was good. The unfortunate part is that I now have to disassemble and clean the entire intake system and I spent $1400 for the turbo and new oil feed line. I’m hoping this turbo is more reliable, and that I don’t have any more issues for a while. This is my first VW diesel and it’s been a disaster. I’m about ready to cut my losses.

could you have just gotten away with buying a cartridge replacement to save a bit of $?
that sucks man, sorry to hear. hopefully you figure things out and the car is there to stay.
its the nature of volkswagens, man. lot of f bombs when things go wrong but they feel amazing when running properly

Damn man. Glad you got to the bottom of it, sadly in the least fun way possible.