1.8 Tqs Down on power

[hardhitter]

I'm trying to get to the bottom of why my 1.8 TQS is down on power. It's not long serviced by myself and the only thing left to do is the fuel filter as it was so awkward to get off and the bolt was just turning without undoing ! I'm hoping the the new fuel filter will help when I finally get the old one off, but I suspect something else may be causing the problems.

Normal sedate driving is fine, but when you put your foot down theres little in the way of boost compared to what it used to be like ! I can't see any obvious boost hoses that are loose or leaking, but I should investigate a bit more. Is there a pressure tester you can use to check them out ?

I have just scanned it with VCDS and the only log was:

00561 - Mixture Adaptation
14-00 - Adaptation Limit (Add) Exceeded

I'm not sure if this is a standard fault code or not.

Would the diverter valve or N75 be a likely cause of boost loss ? Or even a clogged fuel filter or blocked up exhaust/cat do it ?

Any suggestions would be great.
Thanks

 

[aragorn]

Its quite likely a leak somewhere, probably on the vacuum pipework or similar.

(Add) means additive adaption, which is most prevelant at idle, and indicates a constant volume air leak, which usually suggests a vacuum hose or similar.

You may find the ECU has deliberately turned the boost down due to that fault code.

 

[hardhitter]

Cheers aragorn. I'll go through the Vac lines tomorro. I'll prob get some new as they tend to fray and come away at the ends and look untidy !