Low Boost but intermittent

[johnnyp]

Hi Everyone,
Have checked through all the threads on boost leaks but still not sure what my problem is. About a year ago I started getting overboost on my '91 3B. On full throttle the engine would suddenly cut (a real shock the first time!!). This happened only occasionally. I unplugged the MAF and plugged it back in and had no more problems until about a month ago. I then noticed that I was only getting 0.4 bar of boost instead of the normal 0.8 and this was every time I put my foot down. I initially thought it must be a leak through one of the hoses or the IC o-ring. But then at the weekend I got full boost again, and then lost it. And this morning I got full boost again! I'm no engineer, but if it's a boost leak I shouldn't be getting full boost now and again! Does this sound like a new MAF is required?

John

[s4_rider]

check N75 valve

check N75 valve

[s4_rider]

N75 valve maybe ?

check frequenty valve (N75 valve)

first the electrical connection (contact cleaner)

if not working

use for example WD40 to clean and smoothen the internals.

what does it do:

http://forums.audiworld.com/s4/msgs/1046677.phtml

[johnnyp]

Thanks for that

Is it an easy job to remove the wastegate for cleaning? Can I do this without taking half the engine apart?

[S2sedan]

yes you can do, but I don´t think you need it ... first go for N75.

[newsh]

http://www.s2forum.com/forum/showthread.php?t=6778&page=5