Hi my name is John. I purchased a 96 XJ for my 16yo daughter for $500. The XJ sat for 2 years and has multiple Cylinder Missfire codes and l can't get it to pass inspection. Since it sat for so long, I wanted to start over fresh. I have changed out the Cap, roter, plugs, wires, injectors, TPS sensor, MAP sensor, and the CPS sensor with no luck. I'm getting the P0300, P0301, P0302, P0303, P0304, P0305, P0306 codes. Random Cylinder Missfire and every individual cylinder Missfire code.

I'm trying to think what would be across all cylinders. I only have 1 coil for all cylinders, 1 fuel pump, fuel regulator, cam position sensor or PCM?

It seems to run and idol fine so it's not a constant Misfire problem. Its unlikely to have bad compression in all cylinders. Its unlikely to have all 6 burnt valves or all 6 injector wires to be bad so your thoughts?

 

Welcome to the forum.

Check and make sure that the plug wires are all correct. Dont just assume they are because you hooked the new ones up the way the old ones were


Have you taken the distributor out and inspected it?

Also make sure that the distributor is indexed properly. Not just guessed at or assumed it is correct.

You'll fit in here. People are very helpful

 

Thanks for responding. I purchased a 92 Jeep YJ for $2200 and spent 3 years and $11,500 rebuilding and upgrading it. I
learned a lot of valuable info that can be utilized across both jeep platforms so I'm not new to the older Jeep rebuild world






I did check the correct wire configuration. Thanks for the insight. I haven't pulled the distributer out yet. What should I be
looking for? I been trying to educate myself on the Cherokee XJ and have been doing a lot of research on the subject. I
have a few more questions.

Would any of these cause the random cylinder misfire across all cylinders?
1) Leaking valve cover gasket
2) Bad fuel regulator
3) Weak or failing fuel pump
4) Low Voltage from a coil.
( My 96 XJ only has 1 coil for all 6 cylinders that I know of)
5) Bad or failing PCM
6) Timing
7) Failing and cracked wiring harness
( the 96 XJ had the injector wires being routed directly over the intake manifold and are prone to heat damage)

When I replaced all 6 injectors, I did upgrade to the 4 pin hole injectors for better fuel atomization and a cleaner burn.

 

I'm moving this to general Stock XJ