Need help diagnosing misfire code

Bkspear

TJ Enthusiast
Joined
Oct 30, 2020
Messages
107
Location
GA
2003 with the 2.5l, engine started running really bad and almost stalled, check engine light came on and code reader says cylinder #3 misfire. I have already changed plugs and wires. What else should I be looking at? Thanks.
 
2003 with the 2.5l, engine started running really bad and almost stalled, check engine light came on and code reader says cylinder #3 misfire. I have already changed plugs and wires. What else should I be looking at? Thanks.
I thought 2003 would be a 2.4?
 
Things that can cause a misfire: Spark plug, plug wire, coil, distributor, injector, injector wiring, PCM, valve, valve spring, piston ring, cylinder head ... should I go on? You need to troubleshoot.
 
Was there any recent work done to the Jeep prior to it running so poorly?

Some simple things to check...

Did you gap each plug?

You could check the resistance on the injector that feeds the #3 cylinder. That would at least tell you if there is a problem on the electrical side. I agree with Charles HS...could be a problem on the mechanical side of things relative to the injectors. A resistance check won't tell you if the injector is dirty or if the spray pattern is not optimal for atomization.

You could pull the fuel rail, with the injectors still in the rail and turn the ignition to the "on" position and see if any injectors are leaking.

Hope this helps.