[200q20v] undiagnosed engine malfunction

[Neil Vonhof]

It's still probably the turbo bypass valve. My engine would die intermittently,
not every single time. Since replacing the TBV I have NEVER had the problem.
It's easy to replace and not too expensive ($40 or so). When I took the old one
out I sucked on the small nipple (the one that the vacuum hose goes to) and got
zero resistance which meant it was blown. The new one pulled a vacuum when I
sucked on it. Also, be sure to check that vacuum line, it goes all the way to
the back of the intake manifold on the drivers side and can oftern be burnt and
crumbly.
Neil Vonhof
Seattle
'91 200q20v 135,000 miles

Bruce Boeder wrote:

> After having had my avant's undiagnosed engine malfunction diagnosed by the
> list as a turbo bypass valve malfunction, I tried last night what Mike
> Miller had suggested. That is, accelerated hard in 3rd gear to +1.5 boost
> and then backed off and depressed clutch simultaneously.
>
> Unfortunately, that didn't make the engine stop.  The boost gauge under hard
> acceleration showed 1.9 bar max.
>
> I did have the previous owner test drive the car and he commented that it
> seemed down on mid range power.
>
> Will report to the list what this proves to be after further diagnosis.
>
> Bruce Boeder (who still likes the wagon, even if it does occasionally
> misbehave)
>
> _______________________________________________
> 200q20v mailing list
> 200q20v at audifans.com
> http://www.audifans.com/mailman/listinfo/200q20v