ok, so I have been having problems starting at random intervals. Sometimes its a struggle for a couple of seconds with the starter seemingly missing/not catching a spark in the engine/ or not enough fuel flowing. Sometimes it starts quick and fires up to 3k rpm or more and gets stuck until it decides to calm down, and other times it seems to have no problem whatsoever. With the longer that I let this problem go, the worse it is getting. I drive 150-200 mi a day for work, so I need a fully functioning vehicle, and this seems to be a never-ending problem with no solution. I have changed out vacuum lines, new fuel pump and filter, new starter, new spark plugs, distributor cap, cleaned out the system, and had the alternator/battery checked. The alternator check was recommended by this forum, but it showed no problems whatsoever. ANYBODY-PLEASE HELP! This is getting to be a costly, frustrating, and time consuming problem. Not to mention the fun I had Saturday taking out a deer on a back country road.

 

is it EFI or carb

 

A year and motor you have would help..

But based on the info you gave I'd say either your IAC (Ideal Air Controller) or your TPS (throttle Position Sensor) 1 or both sounds like could be your problem..

Also how old is your battier? Just cause they check out good don't always mean they are. Exp. of this, my brother '99 XJ had a random start problem that got worse. He had the battery tested showed good. But when you put a volt meter on it at start it dropped to 9.8 volts below the 10.8 volts a OBDII computer needs to start..

 

My XJ is a 1987, and has the EFI 4.0, though it may be a little different than the rest, I'm not sure. The model I have is from the last year AMC owned Jeep, and I don't know if there are any significant differences in the design compared to the current breed. As for the battery, I don't actually know how old it is, same as when I bought the vehicle, but I have had no other problems that would indicate a bad batt. Will check into it, though.