Originally Posted by Maverick H1L
The IAC isn't working... You're supposed to cold idle about 1200 RPM and hot idle at about 8-900 when in Park/Neutral and about 650-700 RPM in a drive range. My engine did the same thing when the IAC was bypassed (thanks to the idiots that put my 3.1 in the car that didn't swap over the idle air pipe!) and again when the IAC didn't work because it was dead. If the idle speed actually RISES when the engine warms up, the IAC is suspect.
Location of the IAC valve? I have a carburated 2.8 i realize many have FI cars, however myc ar has a high idle in park and some say it sounds as if it is "racing"... sounds like its right about 1200RPM. I adjusted the "Screw on the rear flap in the carb" and now it idles nice and low in drive, so thats good.. Hot idle? Well, if its in park it still idles high one guy even said it sounds like it is "racing."
isnt second suspect a vacuum leak? how to detect? (And what did me screwing the mixture screw "in" accomplish?" it used to idle high in drive too. Not anymore.. my engine was a turnin fast for a long time, not as much so now, only in "P."
I have same issue. Car runs well, particularly when warmed up it sometimes takes a few minutes of weird hesitating to run smoothly. Thats my chime-in, ill follow for more info, thanks