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Discussion Starter #1
I have a customers 99 Jetta TDI in my shop, and I guess I'll give ya the whole story.

Car came to me 3 months ago for low power. I swap MAF, Set IQ, set timing, Clean VGT, clean intake, already has EGR delete, swapped N75, Vacuum test VGT actuator (hand held vac pump while driving) VGT moves freely and with correct travel. No exhaust or intake leaks. I can NEVER get more than 1400 mBar MAP. Removed CAT, same prob. So I play with this thing for 2 weeks and the customer get impatient and takes it to the dealer "who knows what they're doing". (btw, this has been a good long time customer!) I don't hear anything for a long time about it.

Then I find out that dealer reflashed the ECM, did a compression check, replaced MAF, replaced the TPS, replaced turbo, and who knows what else. They had the car for 7 weeks, and finally gave up.

Now the car is back at my shop, I'm going to try swapping the MAP sensor tonight even tho it reads 1003 mbar with engine off, and a max of 1400 with a nice smooth sweep. Next I'll swap ECMs, and then what?

I've read the whole low power, limp mode, uncommon low power, the whole [email protected]%m internet, etc.

Car used to have Kerma's tune, but that's gone after the dealer got ahold of it.. Maybe I'll just have jeff at rocketchip flash it and cover up the problem for them:panic:

I'm just pulling my hair out, any ideas?
 

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Is it coming up with specific fault codes? The car runs sweet but just lacks oomph?
Does it rev up no bother?
Dealers, no wonder they get a bad name and that must've cost a fortune too.
 

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Discussion Starter #3 (Edited by Moderator)
Absolutly no codes. And a little more info that I forgot in the last post.

This is NOT limp mode
Step on pedal, feels like it's gonna really get on with it for just a sec, than it looses it and feels like lower power than limp mode, back off pedal, and in picks up just a little.
When foot is down, it does put out a slight haze of black smoke, and when I romp on it in the shop it puts out good little black puffs.
Injector pump was replaced 1 year ago for a legit problem with it ;)
No air bubbles in fuel, good flow, and even tried a dodge lift pump.
Starts and runs smooth and sweet.
 

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How are the small vacuum pipes? have they been replaced at all, the black smoke to me suggests to much fuel but I'm no expert so could be talking bull, do you know if it's had bigger nozzles fitted too? I've only ever had a similar throttle feel when my car was heading for limp mode but after I stripped and cleaned everything and replaced all the vacuum pipes (wether they looked bad or not) it's been great but you're saying all the cleaning stuff has been done so if the vac lines haven't been changed it might be worth a shot as they're really cheap and easy to do. It might be worth checking ecm/ecu is nice and dry too because mine was soaked through when I got my car and it gave me a few problems but was fine once dried out and resealed. I don't know what else to suggest at the moment and can understand why you're stuck.:)
 

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Hi, when you are looking at the live data on the scanner, what are you getting for TPS position in %? is it smooth increase or does it suddenly decreases then increases?
 

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Discussion Starter #8
Hi, when you are looking at the live data on the scanner, what are you getting for TPS position in %? is it smooth increase or does it suddenly decreases then increases?
Smooth to 100%, and the dealer replaced it anyway:dunno
 

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Discussion Starter #9
just had inner cooler pipe gasket fail,(according to dealer) it acted similiar
Not here, the whole intake system is airtight except for the PCV
 

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I'm inclined to think nozzles, or intake. I bought a golf that the intake had been cleaned out, and everything else that you could imagine was done to it. But whoever cleaned the intake out didn't do a good enough job, I put bigger nozzles on the car because I could see the intake had been cleaned, I got no improvement. I had never seen a tdi with an intake so bad it actually slow the car down but since I had a spare intake we swapped it out, man, that car came to life with that new intake...haven't done any work to it since.
 

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Question...

Hey Schafer...

You said in the original post the the actuator moved freely and from stop to stop. did you check the pressures as mentioned in the setup section?

The pressures absolutely have to be as described in the setup section.

Movement proper movement does not guarantee proper operation. If the movement is at the wrong pressures then it will not allow for proper boost levels.

You are probably all over this. just my 2 c.
 

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I have neerly the same problem sooooo whats the fix? I have one of the N75 dealieos on the way as we speak.. sound like Im pizzin in the wind.. ?????
 

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Plugged intake?
 

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if the code being produced is overboost, wouldn't the car feel extra peppy? My golf gives the overboost code(verified by Vagcom) and feels like such a dog!

What am i missing, where is the boost going?
 

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if the code being produced is overboost, wouldn't the car feel extra peppy? My golf gives the overboost code(verified by Vagcom) and feels like such a dog!

What am i missing, where is the boost going?
no where if the intake is plugged..

over boost can send you into limp mode.
 
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