RE: WARM START PROBLEM

[Paul.Heneghan@bbc.co.uk (Heneghan,Paul)]

This is quite a common problem with VWs, Audis and Porsches.  It is due 
 to vapour lock, where the fuel in the fuel lines near the engine 
 vapourises due to either excess heat, or excessive loss of fuel pressure.

If engine bay is too hot, check things like fans, thermostats, 
 radiator, timing, mixture, engine oil, etc.

If loss of fuel pressure is the problem, this is likely to be a leaking 
 injector (remember to check the cold start one as well) - these should 
 not dribble any fuel when the fuel pump turns off.  Other things that 
 could be responsible are the accumulator, and the check valve on the 
 output of the fuel pump.

If you can't be bothered with any of the above, then there is a 
 modification (included as standard on later model cars) to pulse the 
 cold start injector during warm starting - this provides enough fuel 
 to get the engine started.  This is done with a special relay with a 
 timer built in.  The poor man's alternative is to wire up a 
 spring-loaded switch positioned under the dash in parallel with the 
 thermotime switch (the one that fires the cold start injector) and 
 when hot starting is a problem, give the switch a blast.

HTH

Paul
----------
From: Rick Johnson
Subject: WARM START PROBLEM
>
>Help needed from the technical Gurus out there.
>
>I have a warm start problem. (It occures occationally when cold also, but
>not a severe.)
>
>The Audi acts like it's flooded after being shut off for more than a few
>minutes. It acts like 2 of cylinders are flooded. Once the RPMs are
>raised three or four times it runs fine.  Cold starts with no throttle
>and just allowing it to warm up three or four minutes is no problem.
>Occationally there is no problem at all on a cold start.
>
>Both gas filters and air filter are new. No compression check has been
>done.
>
>Could an injector be leaking fuel into its cylinder after the car is shut
>off?
>
>I live in a rural area where most local mechanics will not touch the car,
>or I would't have them touch it.
>
>Any insite to my problem would be much appreciated.
>
>Rick Johnson
>www.ricky@psln.com
>
>