I have a 99 jeep grand Cherokee laredo 4.0 6 cylinder, I start the engine, the idle jumps up and down, reving up, then down over and over, then I put it into drive and it dies. When I do get it started and start driving, in about 15 seconds, the idle begins the go up and down. Almost seems like its not recognizing what gear its in.
I have already changed the crank shaft sensor, cam shaft sensor, ignition coil pack, and new platinum spark plugs. I'm still getting the check engine reading of p0353 and 1391, one is for the crank/cam shaft position sensor and the other is ignition coil malfunction , I have replaced all of these and they have not solved the problem. Can anyone please help me. This is my only vehicle and need to get it running. Please help!

 

I was having similar issues with my 95. I found some damaged wires going to the ignition coil. It was causing the signal to fade in and out. I repaired the wires and now she runs like a dream.

 

Where does the wire from the ignition coil pack go from there? To the powertrain control module? Or where to get a replacement wire? I haven't had luck with anything else. Thanks for the help.

 

I started right at the coil and followed them back. The do go to the pcm. I actually just cut the damaged pieces out and soldered them back together. The damaged section was vary close the the coil its self.