Hard start, cold start problem, rough idle

[Derek Pulvino]

Bryan,

I've been having the same problem for a while, and notice it also does go 
away in the colder months...in fact now that's it's warmer again, when I 
restart my car when it's warm, and last ran within an hour to two, the car 
won't idle at all without me keeping my foot on the gas...that condition 
lasts for at least 10-minutes.  Also notice the rough running when I restart 
the car, lot of stumbling for a couple of minutes and the check engine light 
will come on, but I get no fault codes.

Right now, my key suspect is the idle stabilizer valve, and I do recall that 
when I last pulled it to check, the flapper/valve seemed to immovable.  Was 
going to do an "output test" when I get some spare moments again.  The only 
thing I can think is maybe this is sticking, and causing the car to be 
overly rich on warm startup...but it doesn't answer the question as the why 
the car wouldn't also do the same once it's warmed up.

Some other ideas I had was maybe the temp. sensor to the ECU was crapped 
out, but resistance at the sensor was within spec when I checked, or maybe 
I've got a back check valve which is letting the fuel pressure decline too 
much between starting...but then I wouldn't have idle problems for as long 
as I do.

All in all, this is quite frustrating and not contributing to a health 
demeanor when I'm on the road.

Derek P

Message: 1
Date: Wed, 28 Jun 2006 17:05:45 -0400
From: "Bryan Foster" <brfoster at gmail.com>
Subject: Hard start, cold start problem, rough idle
To: 200q20v at audifans.com
Message-ID:
	<9be3f0980606281405v257c1184q199efc0a6c4b9464 at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Listers,
I have had a couple of weeks of rough idle during cold start ups.  The car
will start easily, but then idle very roughly for 30-45sec.  After that time
it runs and idles very smoothly.  If I start it up and immediately rev the
engine to >2000rpm then it runs very smoothly, but if I was to let off the
gas and let the engine slow down to idle then it sputters and nearly
stalls.  When I rev it up right after start up there is a considerable
delay btw putting my foot down and engine response as if the mixture is way
off.   It seems to happen if the car has been sitting for >1 hour.  Not
necessarily a completely cold block.  Does this point to anything in
particular.  Leaky injector?

Thanks in advance,
Bryan Foster