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high idle in park after being in gear

MONSTERxbla

NAXJA Forum User
Location
Fresno
I have searched....replaced tb with a bbk 62mm, after install noticed that the idle was a little more erratic than I remembered (about 750 rpm) but seems to vary +- 30 rpm (I have a scangauge 2). after a short test run I notice that upon putting jeep in park the rpm's were about 1100rpm, I blipped the throttle thinking maybe linkage was binding, no effect. if I turn the jeep off, then restarted, the rpm's go back to about 750rpm. I checked for any obivious air leaks, found none. I pulled the iac and cleaned it. I noticed a little bit of play on the plunger, I am thinking this may be the problem. the issue is very consistent, only happens after putting jeep in gear. thanks in advance.
 
Sounds like you are onto both candidates, which are vacuum leak and IAC.

It's easy to get a vacuum leak. You should hook up a vacuum gauge somewhere and see if you've got one.

On the latter possibility, the computer will hunt the IAC initially to look for right idle, starting at 2k RPM and going down to stall, then back up to steady low idle. The computer may still be trying to work the old settings with the new TB, so if you haven't done so already you should reset the computer.
 
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