S2 stops accelerating when given full gas.

[Jonas_R]

Hi

S2 Coupe 1992
Tuned by hohenester in Germany to 310 HK ~ 1.3 bar boost,

When i floor the gas pedal, my car stops to accelerate, it hits around 0.8-0.9 bar bar then the car shake and it stops for an instance to take gas... Normaly it will take full gas.

This happens in the 2nd, 3rd and 4th gear, haven't tried 1st og 5 th gear.

I had a similur problem, but there the problem accour at a specific RPM and it was fixed... And the car could easyly take 1.3 bar but it cant now.

Can the engine somehow be in safe mode and disregard the hohenester setup, if yes how do i turn it off?

Any other suggestion is welcomed...

Jonas

[andre]

Hi Jonas

Almost 100% sure that you have an air leak in your turbo to inlet system somewhere. Have a search through this forum and you will find a number of references to this problem along with some instructions on how to test.

It's also known as the WOT (wide open throttle) problem or Overboost protection (not to be confused with overboost on it's own which is very cool).
Sadly there are a great number of possible leak points, some of which are very small, but all of which can cause the problem you are having.

Happy hunting, it's a royal PITA to find the cause.
Andre

[APNess]

Check the clip to the big pipe going to your throttle body. I had the same problem after I replced the clip with a shiny new one. Put the old crap one back on and and boost was restored - I couldn't get it beyond about .8 bar as I recall. Put old one on, back to 1.4

Other than that, check ALL your clips. and if they all tight, then you got a leak in ur hoses, which is par for the course with 10-12 year old cars, I'm afraid.

PJ

[Jonas_R]

Where can i locate the TB? Is it from the MAF to turbo or from turbo to IC or from IC to intake manifold?

Bit confused with the TB word, perhaps a picture would do some good!

Jonas

[APNess]

Tsch. 12mp camera and I spend most my time taking engine pictures with it

The bits with yellow arrows are the obvious ones to check (imo). After that, you gonna need to get your hands dirty I'm afraid

The top one was the one I had bother with - Mihnea mentioned that the sludge around it indicated a leak, so I changed the clip. Then I DID get a leak, so I changed it back, and I can live with the sludge It's getting a new intercooler anyway, and I'm dreading seeing what the accumulated crap in a 10 year old i/cooler looks like :S

Good luck!

PJ

[Jonas_R]

Oki well my modified car does not look like that...

Here is a picture, and teste the to little pieces for leaks and there was none. However i cleaned the MAF and that seemed to cure the problem

http://www.skumlern.dk/Audi.s2/PA120098.JPG

/Jonas