My 90 240 wagon has a warm up problem. Upon start up, when cold, it will race at about 2500rpms for about 30 seconds then gradually drop down to a normal idle of about 900 rpm and will idle fine afterward. If it is really cold, it will stall after about 15 seconds, it will restart without any problem and repeat the 30 second exercise. Any thoughts?
Poorgie

Might be other ideas, but what B.C. says is the *best* place to start.
--
Thank goodness we don't get all the government we pay for. -- Wiley Post

One could theorize that your brick is talking to you,saying "It's too ____ cold, leave me be!". But that doesn't get the job done, does it?

Often a high idle is a result of a problem with thte IAC. I have no an idea about how a cold ambient temp could have any effect there, though.

With a pair of pliers in hand, and the hood open, start the car and while it is still in its high idle stage, use the pliers to slowly close off one of the hoses from the IAC to the intake manifold. Either hose will do, grab the nearest one. If that slows the idle, the problem is in the IAC system.

My first thought would be do make sure the throttle position switch was working OK. If it isn't telling the ECU that the plate is closed, the ECU won't tell the IAC to start controllng idle speed.

My second thought would be to clean the IAC. It's a good idea to have it off the car. Then you can hold the IAC with the harness end up so as to have any carb cleaner not run into the electrical end of it.

There surely are other ideas.

Good Luck,

Bob

:>)

Bob
Thanks for the reply, I did cleen the IAC a couple of weeks ago, and it didn't make a difference. I did not however try blocking off a hose to prove that out. I thought about the throttle body too, but I don't get how that would be so temperature dependent. Thanks again for the response


Poorgie

This may or may not help...and watch this thread opposite symptom but an IAC problem.


http://brickboard.com/RWD/index.htm?id=1159962