I tried to start my 97 TJ yesterday and failed to hold the key over to start long enough. The engine coughed back through the intake; I started it a few moments later and it raced at 2K rpms. I disconnected the negative battery cable and left if off for a couple of minutes to see if the computer would reset, no joy. Next I took off the throttle body and cleaned the connections to the TPS and MAP, and I removed and cleaned the IAC. It idles somewhat lower now (18K). The check engine light isn't illuminated and haven't checked for codes. How can I test the TPS or MAP to see if one of them is the culprit, or is there some other source of the problem? Thanks!
97 TJ hiccup on starting, now idles waaaay fast
Bounty__Hunter
Super Moderator
A high idle is generally a vacuum leak, I'd double check the installation of the throttle body and all the sensors.
Throttle body and all sensor connections good and tight, what I found was a vacuum boot that has apparently popped off when the engine coughed back through the intake. A handy can of spray cleaner helped me find that. I put the boot back in place, reset the computer for good measure and it runs like new. Thanks, Bounty Hunter!
Bounty__Hunter
Super Moderator
Good to hear.
