High Idle

I have a '89 LeBaron ( H body ) T1 with a high idle problem. Sometimes I have a high idle of 2200 RPM or so and other times car idles perfect. Have checked out vacumn lines with propane and thought i found a bad vacumn line off one of the ports of the throttle body and I replaced it. No codes are found. I shot fuel injection cleaner through the throttle body but the high idle returned. Would a bad or out of range AIS solenoid cause this ?
Maybe the Mopar Performance computer doesn't show a bad AIS ?


Jim

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Originally Posted by dodgeman87

I have a '89 LeBaron ( H body ) T1 with a high idle problem. Sometimes I have a high idle of 2200 RPM or so and other times car idles perfect. Have checked out vacumn lines with propane and thought i found a bad vacumn line off one of the ports of the throttle body and I replaced it. No codes are found. I shot fuel injection cleaner through the throttle body but the high idle returned. Would a bad or out of range AIS solenoid cause this ?
Maybe the Mopar Performance computer doesn't show a bad AIS ?
Jim

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Hi Jim.
With known good vacuum lines and free of leaks..
The TI has a DC motor with a small plastic planetary gear set that opens and closes a 'shutter vane' assembly.
These can require cleaning or replacement over time and may be worth investigating.
When removed from the motor, the shutter and gears should effortlessly and freely open and close.
If not, the plastic has minor scores or contamination has built up and in both cases should cleaned/corrected.




DC Turbo-I AIS Motor (Internet Photo)
Attachment 46905

If it is the suck through type, a loose turbo hose will make it idle right in that range. The loose hose basically bypasses the throttle body. I figured that out when it happened to me.

I am having this problem with my TI 86 Daytona Turbo Z. However, mine seems to be idling around 3000 RPM. No vac leaks that I could detect, and I have replaced the AIS motor, granted with a used one, but sometime it idles just perfect and other times it will idle at that high RPM. Sometimes it will idle high for a few blocks of driving than calm down. Mine too has a Mopar Performance logic module. Wiring harness is pretty well hacked, and I plan to install a good used one this summer. Would a loose turbo hose cause this high of an idle?
-Lee

On a TI log car any vac leak will cause an exceptionally high idle. I would certainly think that a loose turbo to intake coupler could cause this too.