My 98 XJ has a misfire. Its a 4.0.

It used to be #1 and #3. When I pulled the injector wires or spark plug wires on those cylinders the idle didnt change. Now, #1 is working correctly and bogging down when spark plug or injector is unhooked. Not as much as the other cylinders make it bog, but it does it noticeably.

Now its just #3. New spark plugs. Getting strong spark. Injector tested good. Valves are opening. Does anybody have an idea? Check engine light is on.

 

I would start with a complete tune up. Wires, plugs, distributor, ext. Throw some Lucas tune up in a bottle in your gas tank, you should be good 👍

 

The wires are fairly new looking and I just seafoamed the throttle body, gas, and oil last week. The problems been present for a few months. I will change the distributor cap though and if that doesnt work ill try the wires. Thanks for the help!

 

If you are getting good spark in ALL cylinders then it's probably a fuel issue. Most likely a failed or faiLing injector (possibly two in your case). That would be my guess any way.