Ive got an 88 cherokee, and i cant get it to run right. Its a 4.0, auto, 4x4. Its running like crap, in park it will rev up, but you have to slowly. If i disconnect the MAP sensor vacuum line, it runs worse, but it will drive. and with it connected, it sounds better, but has absolutely no power when drivin. I was thinking a vacuum leak, but i cant find anything major. Any suggestions?

 

Tuneup hardware. Plugs, plug wires, distributor cap, rotor. Basics first

Test AND adjust your throttle position sensor. Critical in tip in of throttle. Your vintage IS adjustable so don't forget that part....

Your map sensor can be tested.

Buy a manual; best money you can spend if you work on your XJ.

 

Ok, so it has new plugs etc. I put a new map sensor on it. Havent tried the throttle position sensor tho. Any other suggestions?