Re: typ44 turbo: stalls out, rough idle

[Scott Fisher <sefisher@cisco.com>]

Chris (JordanVw@AOL.com) asks:

> why would the abrubt drop in rpms cause it to stall? 

One classic cause of this behavior is a largeish vacuum leak. 
Sufficient throttle opening will mask it, because enough air is coming
in through the measurement plate that the fuel mixture is close, but
when you close the throttle, the mix leans out to the point where it
won't run.

The hunting idle can also be a symptom of that.  One way to locate a
leak (assuming you can get the car to idle at all -- a helper in the
driver's seat can do the trick) is to spray carb cleaner on various
suspicious locations and notice if the revs drop.  Carb cleaner is
non-combustible, so if it gets into the inlet tract the revs will drop.

Which reminds me: does any enterprising aftermarket parts supplier offer
a "complete vacuum hose" package for various configurations of Audis? 
It's a common experience for older cars to start cracking or splitting
vacuum hoses, as the underhood environment (especially on turbos) is
very harsh to plastics and rubber, and I've always felt that visible
deterioration is just the tip of the iceberg -- it's the cracks you
DON'T see that are most likely to split on you when you're out in the
wilderness enjoying yourself.

I've often thought that I'd pay an appropriate premium over the cost of
the hoses to anyone who did the work to research and put together a
package that had *everything* in it.  Purchase it all at once, spend an
afternoon installing all the lines, and just be done with it for a few
years.

And y'know... this could be a good Web application, for someone with a
good database of Audi parts; let the user select year, model, and other
necessary variants, then click "order" and have the Web app build a
comprehensive list.  Then unselect the bits you *knew* you've just
replaced and order everything in one massive credit-card hit.

Any Web-connected parts houses out there with access to a good Perl
programmer -- I'll beta-test it for you and put in your first order,
too. :-)

--Scott Fisher
  '83 Audi Coupe GT
  '74 Alfa Romeo Spider Veloce
  '67 Alfa Romeo Giulia GT 1300 Junior