How do you test IAC Valve?
Thread Starter
Cruising
Joined: Aug 2004
Posts: 13
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How do you test IAC Valve?
82 CF doesn't start cold on it's own, and idles lousy warm. Fouls plugs
badly. Creating a vacuum leak makes it ilde faster. Tried to ground the
ALDL and see if they would cycle ,but didn't hear anything. Is there a
better way?
Thanx,
Frazzled.
badly. Creating a vacuum leak makes it ilde faster. Tried to ground the
ALDL and see if they would cycle ,but didn't hear anything. Is there a
better way?
Thanx,
Frazzled.
Pro
Joined: Dec 2000
Posts: 531
Likes: 0
http://www.thirdgen.org/techbb2/foru...php?forumid=17
A lot of the TBI troubleshooting tips apply. Try this link. It's been helpful to me.
A lot of the TBI troubleshooting tips apply. Try this link. It's been helpful to me.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
They only cycle with engine off and ign on, aldl grounded. So, stick a clip between the terminals and go look if they cycle in & out.
IAC's hardly ever go bad, linear stepper motors are very reliable. They do tend to get dirty, clean them with some brake cleaner (after you pull them out), also make sure the gasket is in place and that the pintle is not damaged.
The cold idle is probably a result of a poor balanced & synched system. Minimum air may have been set incorrectly or the idle stop tangs on the linkage could have worn to the point that idle gets lousy and choppy. Worn tb housings (the shaft is mounted in the aluminium, there are no bushings installed) will give a lousy idle also.
Have you ever checked the coolant temp sender? It's a very common cause for overly rich running, plug fouling & crappy idle.
IAC's hardly ever go bad, linear stepper motors are very reliable. They do tend to get dirty, clean them with some brake cleaner (after you pull them out), also make sure the gasket is in place and that the pintle is not damaged.
The cold idle is probably a result of a poor balanced & synched system. Minimum air may have been set incorrectly or the idle stop tangs on the linkage could have worn to the point that idle gets lousy and choppy. Worn tb housings (the shaft is mounted in the aluminium, there are no bushings installed) will give a lousy idle also.
Have you ever checked the coolant temp sender? It's a very common cause for overly rich running, plug fouling & crappy idle.
