I have been trying to diagnose a misfire issue and I am having no luck. 1995 zj with the 5.2L v8. I am wondering what the symptoms of a bad pcm are? My jeep is runs very rough and sometimes hard to start.

I have replaced cap, rotor, wires, plugs, coil, fuel filter, and nothing has worked.

Thanks.

 

There is a plate at the bottom of the intake manifold that has a gasket that can blow out and cause a vacuum leak and misfire. I highly doubt that the PCM is causing the problem. You may also want to check the fuel pressure, could be a weak pump.

 

Mine had similiar symptoms, would be hard to start when hot. Was the crank sensor, will cause a misfire too.

 

pcm's rarely go bad but are commonly blamed