Thursday, June 25, 2015

Grand Cherokee 4.0 has a stalling problem

Question:
My 1997 Jeep Grand Cherokee 4.0 has a stalling problem. I have checked the basics (plugs, coil, rotor, crank pos sensor). When it stalls it stops like it was turned off. will often restart and run OK for a day or so, sometimes a few weeks

Answer:
If the crank position sensor has been replaced. then with the switch of type situation it usually comes down to a bad pcm or a 5 volt sensor feed shorting.
the main places I look for a short are the back corners of the head. at the area of the distributor and the oxygen sensor wires specifically the rear o2 hitting the drive-shaft.