Stumped

Need some help from the gurus here.
Have a 2003 Golf 5sp. 278k on it.
New fuel filter, new air filter, recently replaced EGR valve that wouldn't hold a vacuum and changed the duty cycle to 59 percent.
Working MAF, checked with VCDS, peg throttle to 4500 rpms and MAF reading jumps to 850, at idle MAF readings are the same called for and actual.
Cleaned intake last May of 2014.
Turbo makes boost, have gauge on it.
Straight pipe no cat.
My trouble is that going down the highway I can't get it to go over 3500 rpms or 85 mph.
When my EGR crapped out and it threw a code it ran better and would peg the boost gauge, now it seems to struggle to build 15 lbs of boost.
Now that I fixed the EGR issue it seems to be down on power.
No excessive smoke, just haze that I can see at night from the headlights of a car behind me.
I have also replaced some suspect vacuum lines.
Currently have no codes.

Any suggestions on what to look at?

Thanks in advance.

Injectors?
If they don't put out it won't go.
What can you tell us about them? How many miles on them?

JETaah said:

Injectors?
If they don't put out it won't go.
What can you tell us about them? How many miles on them?

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Original as far as I know, 278k on them if they are original.
I don't have any history on the car I brought it with a 108k on it
from a VW dealer, it was a manufactures buy back because the lady said it made to much noise
I got a set of used ones and tried them and it actually seemed worse.

Also cold starts no problem and no smoke that I have noticed.

Restricted fuel pick up in the tank, maybe.
Have you been using biofuels in the past?

278K on the injectors is not good news and if you changed them out with something that is worse then you can see what effect it will have.

Did you check the intake ports in the head for restriction when cleaning out the intake?

No biofuels, straight Diesel from pretty much the same fuel station, I have other Diesels and get fuel from same place so I don't suspect the fuel station.

Intake ports looked pretty when I had the intake off May 2014..

I have 3 MAF's a chinese junk one that it runs really bad on.
A Bosch one that I am not sure how long it's been on there but I did buy it new.
And now a used one that seems to be working the best.

When it was in limp mode becasue of the bad EGR (wouldn't hold a vacuum) it seemed to run the best.

I just the EGR mod thread over again and put the EGR duty cycle back to default, will test drive later and see how it is.

legendman said:

When it was in limp mode becasue of the bad EGR (wouldn't hold a vacuum) it seemed to run the best.

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When it was in "limp mode", what was the code in the ECU memory?

Not opening the EGR valve due to a torn diaphragm in the actuator won't put it into limp mode as in protecting the engine from a potentially dangerous condition by cutting fuel back.

JETaah said:

When it was in "limp mode", what was the code in the ECU memory?

Not opening the EGR valve due to a torn diaphragm in the actuator won't put it into limp mode as in protecting the engine from a potentially dangerous condition by cutting fuel back.

Click to expand...

P0672 Cylinder 2 Glow plug fault
P0234 Boost Pressure Regulation Limit Exceeded
P0401 EGR Insufficient flow.

I think that the P0234 puts it in limp mode due to an overboost condition. That will take the wind out of your sails by cutting fuel back.
Do you have a mity-vac hand pump?
Need to see how your turbo vane lever reacts....is it getting stuck.

The glow plug fault wont have anything to do with this.

EGR insufficient flow to be related to the vacuum leak at the EGR actuator and it may be playing havoc with anything else operated by vacuum.

Make sure that the turbo lever can move smoothly full stroke and that the actuator can be pulled incrementally with the mity-vac.

JETaah said:

I think that the P0234 puts it in limp mode due to an overboost condition. That will take the wind out of your sails by cutting fuel back.
Do you have a mity-vac hand pump?
Need to see how your turbo vane lever reacts....is it getting stuck.

Make sure that the turbo lever can move smoothly full stroke and that the actuator can be pulled incrementally with the mity-vac.

Click to expand...

I put a used turbo on a year ago with a new actuator, tested with mity-vac and was working good.
I will check it again when I fix my down pipe.

One I notice is when I push the accelerator pedal it seems like it's delayed, the boost starts to rise but the power isn't there.

At what vacuum reading does the lever start to budge from home position (fully up lever)?

And then, what reading does it hit the stop screw (fully downward)?

Was pulling a long hill last night and the check engine light came on.
Haven't checked the codes yet, but I but it's the same Boost condition code.
Your suggestion about the vanes sticking could be the issue.
I have another turbo that I can put on..
I will check the codes tonight

legendman said:

Was pulling a long hill last night and the check engine light came on.
Haven't checked the codes yet, but I but it's the same Boost condition code.
Your suggestion about the vanes sticking could be the issue.
I have another turbo that I can put on..
I will check the codes tonight

Click to expand...

Before pulling the turbo, check to see if the actuator is not the sticky part. Yeah, I know you replaced it with a new one. Was it the real deal or an Ebay special?

Another thing...
If you did have a torn diaphragm in the vacuum system somewhere now or in the past, it could have sucked up dirt and loaded the hoses and PWM valves with debris that is causing the vacuum to not vent quickly enough. That will also cause an overboost condition.

Went to get some parts from another member here and on a long hill the check engine light came on and it started running a lot better, more power like it used to be.

But the code is for a Glow plug fault

Tuesday,01,September,2015,20:01:41:53403
VCDS Release 15.7.0: Generic OBD2
Mode 03: Emission related fault codes

Address 0A (Engine): 1 Fault Found:
P0672 - Cylinder 2 Glow Plug Circuit (Q11): Electrical Fault

Which I don't think would put it in limp mode, maybe I'm wrong.

Is it only top speed and not rpm that's limiting on you? Can you readily rev past 3500 in a lower gear?

I don't see any mention of checking your snowscreen. If you've got one then take a look at it. Not sure if it's the source of your problem, but it might add to the problem (plus, it's easy enough to check while you're trying to think of what the source of the problem really is!).

VCDS and logs, priceless!

I cleared the codes last night and it ran pretty good on the way to work this morning.
Still seems to be some turbo lag, but it's much better... so like JETaah mentioned before, I need to get the vanes checked out..

I thought for sure the code would be for a overboost condition but it wasn't.

UhOh when it was running like crap it seemed to struggle building rpms..
best I describe it.. felt like boost was there but no fuel...and a delay when pushing the accelerator pedal (which had me suspecting the MAF, but it checked ok with the VCDS)

When I'd gotten my car I could see it would boost, but the thing really struggled to increase rpms. It actually felt like it was hitting the proverbial brick wall; I'd keep it pegged and it would increase rpms, but only reluctantly and would kind of hit some bigger rpms gains, but not a lot. All of this disappeared after cleaning a horribly clogged intake.

I cleaned the intake May of 2014, I wouldn't think it could be clogged that quick especially with the EGR not holding a vacuum and being able to open.

I checked the snow screen, looked clear, took it off and blew it out.
Also put the mity vac on the actuator and it moves no problem.

On the way to work it ran pretty good, coming home it was down on power..

Like the title says I am stumped...

I think I am on to something, yesterday and today it ran good going to work.
27 mile trip, power was good, going home yesterday it was down on power.
70 degrees in the morning and high 80's in the afternoon.
I am pretty sure I read somewhere that the MAF has a temp sensor in it also..
Plus even with it running good this morning it would rev to 3500 rpms then struggle from there, I think it topped out at 3700 rpm.

My symptoms are about the same as this thread...

http://forums.tdiclub.com/showthread.php?t=439096&highlight=runs+cold

I don't suspect the vacuum line going to the actuator though, I replaced the line last year and I tested it last night when I got home from a 27 mile drive and it was plenty warm under the hood..

I just ordered a new MAF, was $56 on epay so I figured what the hey.

That's my thoughts, I suspect the MAF. I quickly ran through the thread, but do you have VCDS? You will need to log some data to get a correct diagnosis on the MAF. I think your testing of the MAF is not adequate.

cleaver said:

That's my thoughts, I suspect the MAF. I quickly ran through the thread, but do you have VCDS? You will need to log some data to get a correct diagnosis on the MAF. I think your testing of the MAF is not adequate.

Click to expand...

MAF checks out ok with the VCDS at an idle and going down the road, but it could have been cool out when I checked.
My laptop battery doesn't last long enough to check over a longer period such as a drive to work.

It was the MAF, put a different one on tonight and the power is back,
will know for sure tomorrow on the drive to work.

Thanks for everyone's help.