CGT upshift light (switch), and smog

[Huw Powell]

> My question now however is about the
> stock upshift light.  Mine doesn't work, but my vacuum advance and
> hoses are good.  I sucked on that little doohickey that is inline
> with the hose to the vacuum advance unit and it leaks vacuum.  I'm
> thinking it shouldn't.  I'm also wondering what it does.  My guess is
> that it is the vacuum switch responsible for the upshift light, and
> its leaking vacuum is the reason my light's not working.  Maybe it
> leaks enough so that the vacuum advance doesn't work either.
> 
> Does anyone know if that's its function for sure, and if so, can I
> just bypass it so that at least my vacuum advance works?

Yes, that is what it is.  You can safely ignore/remove/unplug it if you 
want.  It shouldn't leak, of course.  Easy enough to bypass to see if it 
makes your car run better.

The upshift light is based, as I recall, on rpm and inlet vacuum - using 
vacuum to sense load.  There is also a tranny switch so it doesn't come 
on in 5th.

> I suppose
> I'd like to replace it with a good one at some point as well.  That's
> probably a dealer-only item, right?

Probably, but it also ought to a be an easy junkyard part, if the 
upshift light matters to you.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/