3.2 cold start problems.

89911 · 08-27-2003, 10:19 AM

Sorry for a boring post, but if anyone with a 3.2 can share what they found to be the culprit, I would appreciate it.

History: The car just got back from the track and ran flawlessly for over 600 miles. Pulled it off the trailer and it can't maintain an
idle.

Symptons: start car and it instantly dies repeatedly. If I start it and immediately feather the gas down to the idle, it will idle, but at a lower rpm and almost stall. If I then punch the gas and let it drop naturally, it will fall below idle and stall. After a few minutes of coaxing it to idle it will eventually pick up its idle and then perform asymptomatically (02 sensor).

Action performed to date: I've bumped up the idle, but this only seemed to help once it had warmed. I checked for loose vacum hoses quickly. May need to go through them better if indicated. I've got adjustable fuel/air ratios but this does not affect the early cold start problems. The 02 sensor is connected. Any correlation to excessive track use (high rpm) and then this problem. Thanks ahead and if there are any key questions anyone need to know, I'll keep checking. Michael.

KTL · 08-27-2003, 11:00 AM

What about the Idle Speed Valve? It acts as a bypass valve when the throttle plate is completely closed. If the ISV is not working properly, it could be messing up your cold idle.

I recall a number of people saying these get gummed up over time and can be cleaned up to operate properly again

How did you bump up the idle?

ISV:

89911 · 08-27-2003, 11:45 AM

The screw in the yellow circle is the idle adjustment screw. Turn counter clockwise to increase idle speed. How do you go about cleaning out this valve you described?

KTL · 08-27-2003, 12:21 PM

I dunno how you clean it other than pull it off and hit it with some carb/choke cleaner.

I recall Chris Bennet talking about this ISV issue. Maybe PM him or do a search?

ZCAT3 · 08-27-2003, 02:06 PM

Cleaning the ISV is quite simple. Take a look a www.p-car.com for some DIY instructions. Have you tried running the car with the O2 sensor disconnected? If it holds an idle without the O2 sensor then you may have found the culprit.

dickster · 08-28-2003, 04:36 AM

you mention it as cold start - is it ok when warm?

the valve is easily checked - procedure is in bently, sorry dont have it to hand.

did you remove anything at the track?

i thought my valve was playing up but it turned out to be the restrictor (missing) in the breather pipes going to the oil filler neck.

Millzee · 08-28-2003, 04:58 AM

i have a similar problem when the cars cold in runs fine, starts fine apart from when i come to a stop and put the clutch in the revs die and it stops, its starts up fine again and this only happens for the 1st minute or two after a cold start

i wonder if its the idle stabilisation valve, the car normally idles at about 750rpm hot or cold

89911 · 08-28-2003, 05:17 AM

It is amazing how something so simple can solve the problem. Removed the valve and did notice some contamination. Sprayed thouroghly with carb/choke cleaner and let dry overnight. Reinstalled and started car. Instantly the idle was at 1200 since I had bumped up the idle speed in an attempt to correct. Lowered it back down to 750 and it stays there rock solid. My guess is that the high usuage and the fact that I use a K&N with my MAF does allow more contaminates then the stock filter. I would think doing this should be done more often, say with every oil change. It only takes about 10 min. Thanks for the help.

KTL · 08-28-2003, 05:30 AM

I'll be expecting a check in the mail. My rate is $250/hr.

Glad to hear that worked out Mike. I've been meaning to clean mine and have been procrastinating about doing so. Think i'll clean mine and adjust the idle this weekend.