Does your AC clutch kick on and off properly?
No need for a code reader. Cycle the ignition on and off a few times really fast and the check engine light will flash which will give the code.
https://www.quadratec.com/jeep_knowledgebase/article-24.htm
http://www.fixjeeps.com/jeep-check-engine-codes.html
One of them should cover you.
12 means the battery has been disconnected or the computer lost power. 33 has to deal with the AC clutch circuit and 55 means no more codes. So if your jeep doesn't have AC there really is nothing to worry about. Is it fuel injected or carburated? In all likelihood the sensors are not causing the issue. Usually the OBD I computers are just about smart enough to say hey this is acting up and not much else. A few models will control idle air control on a fuel injected vehicle or electronic ignition but beyond that they will pretty much run without a computer hooked up.
If it's carburated get some carb cleaner and hose out all the jets and such. If it's fuel injected pull the idle air control valve and clean the junk off of it and then hose down the throttle body with carb cleaner (may also be "intake" cleaner but it's the same stuff). Those would be my best guess. If it's carburated and you had some crud drop in and then swell up it could be pluggin a jet when it warms up. Fuel injected it's not uncommon for the IAC valve to get a bunch of crud on it and then the butterfly to have some gunk around the edges, when the IAC closes up some to kick it off of fast idle then it almost literally shuts off all the airflow into the engine. Can also check for cracked vacuum lines while you are there, fast way to find a vacuum leak is to get a can of starting fluid and give a little spray around a line, if there is a leak the idle will increase for a second. Fast way to find an area to check, but don't lite your hair on fire while you do it.
Will the jeep just cut out, or does it ever die and not restart until it cools off?
Enter your email address to join: