I just finished putting a new Head Gasket, Oil Pressure Switch, Plugs, Wires, Thermostat and every other gasket imaginable in my 1996 XJ. Was super excited to get it back on the road since it dies 2 weeks after I bought it!!!

Now it runs like Sh**!!! It has givena code of a Multiple Cylinder Misfire as well as a #4 Misfire!

I took out the plugs and #6 was foulded out already and then looked at my air filter and it is covered in oil, with a puddle of oil in the housing!!

I am slowly losing my patientence with this XJ, any suggestions on where to go next??

 

Were all of the plug wires snapped all the way down on both ends, and connected in the correct order?

 

Yes, I triple checked all of the plugs and wires. I wanted to make sure I wasn't being an idiot!

 

Do a compression test and make sure you have the spark plug wires in the correct order?? Other then that check that the wires going to your injectors are correct and spray around with carb cleaner to see if you have any vacuum leaks. Good luck.

 

There is a TSB for the 4.0L entitled "TSB #0900303 4.0L multiple cylinder misfire". http://www.wjjeeps.com/tsb/tsb_wj_0900303.pdf
Might, or not apply to your case.

 

The whole situation is very puzzleing because up until the day the head gasket blew it ran like a top!!!

 

compression test....