help with cold idle
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 4
From: Austria
help with cold idle
hi all..i have the following problem...
(car is a ´90, manual six)
when starting my car cold, i have to coax it with the throttle, other wise it dies....when the temperature comes up, i can go off the throttle..other way round, i opened the throttle blades more, so the cold idle is ok, but it gets too high, when the engine warms up..my IAC counts are 160 when cold, so i think maxed out, and about 50 when hot
is there something i can do?
thank you
(car is a ´90, manual six)
when starting my car cold, i have to coax it with the throttle, other wise it dies....when the temperature comes up, i can go off the throttle..other way round, i opened the throttle blades more, so the cold idle is ok, but it gets too high, when the engine warms up..my IAC counts are 160 when cold, so i think maxed out, and about 50 when hot
is there something i can do?
thank you
Pro
Joined: Mar 2003
Posts: 629
Likes: 20
From: Texas
As I recall there is a little stepper motor on the side of the throttle body which drives a plunger. When cold, the plunger is all the way out and it closes as it warms. The plunger controls air flow of a path around the buttlerflys. The ECM controls the amount which it is open to set the idle. . When I worked on mine years ago, I found it was the path had become clogged. Once cleaned, the problem was solved.
Last edited by split63; Mar 4, 2007 at 02:54 PM.
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
As I recall there is a little stepper motor on the side of the throttle body which drives a plunger. When cold, the plunger is all the way out and it closes as it warms. The plunger controls air flow of a path around the buttlerflys. The ECM controls the amount which it is open to set the idle. . When I worked on mine years ago, I found it was the path had become clogged. Once cleaned, the problem was solved.
Burning Brakes
Joined: Feb 2007
Posts: 786
Likes: 6
From: Manassas VA/Flagler Beach FL
St. Jude Donor '13,'19
I've had similar problems. What size socket removes the IAC for cleaning? If you adjust the throttle body stop screw, does that change the TSP voltage? Why else shouldn't you adjust it?
Team Owner
Joined: Jan 2003
Posts: 20,301
Likes: 240
From: Summerland B.C. Canada
It's best to remove TB to service IAC and bore. If you adjust the min idle screw, you may put the TPS voltage out of spec.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 4
From: Austria
hi all, and thank you
i little clarification...
i run this on my 396, and the TB and everything are new, so no dirt there (at least, i hope ;-) )
i just think, the engine gets not enough air when cold, so i hope i can extend the range of the IAC somehow..
best regards
i little clarification...
i run this on my 396, and the TB and everything are new, so no dirt there (at least, i hope ;-) )
i just think, the engine gets not enough air when cold, so i hope i can extend the range of the IAC somehow..
best regards
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