Ok so I have a 94 XJ and the motor 4.0 threw a rod, so I bought a 91 XJ with a rebuilt motor 4.0 and ran fine had no problems, I bought the jeep just for the motor so I pulled the motor did some painting and put all my parts for the 94 on the 91 and I don't have spark at the distributor on 2 and 5 cylinders, I've tried 3 different distributors and 3 different distributor caps and 3 different rotors and 12 different injectors and still no spark plug 2 and 5 are wet and black the rest are clean, so what else is there to check ? Any help would be great thanks

 

Which flywheel/flexplate did you use?

 

I used the one off the 94 do to the CPS being for the 94

 

Good. So you swapped in the 91 block and head and retained everything else from the 94?
IIRC 2 and 5 fire off the same notch in the flywheel, that's why I was curious. I still think the problem is somewhere in that area.

 

Yea I put everything from the 94 on the 91 block so do you thank the CPS could be going bad or what the flywheel just has holes in it and only goes in one way that I know of so worked fine now don't umm ,.... Idk I'm stumped

 

Is it timed right from when u swapped the distributors?? i.e. cylinder one at tdc when rotor is pointing at 1 on the cap. Sounds out of time to me. Cylinders are sparking but only when theres no compression so its not burning the fuel.

Firing order correct? 153624. 1 is the 5 o clock position if your looking at cap from the passenger fender. Order goes clockwise.

 

Even if timing off spark will still be present. Try switching spark plug wires from known good sparking ones ....

 

Yea I've timed it and timed it Cain had some play so went and got a while new timing set so no play and it's dead on and changed the wires out of 3 sets every wire only on 2/5 still don't fire, could the CPS be going bad not sending the spark ?

 

Not sure if the CPS would be so 'selective' regarding 2 and 5, but could be wrong...

 

Yea is was thing the same thing but I'm trying to look over everything cause I'm running out of options

 

Was fly wheel rusty ? Are you using different cam sensor with each dist ?

 

No, the only thing I can come up with after asking around is that the CPS if bad/going bad or I messed it up win putting the motor back in or bent flywheel that's all I can come up with but idk if that's the prob or not

 

Maybe the cps is seeing something on the flywheel around or near the #2/#5 trigger hole. Possible damage maybe tricking cps to fire at wrong time? Just thinking out loud.

 

Same here it cant tell what cyl its on it just works or it don't....

 

Yea I'm going to pull the starter and look the flywheel over and take some sand paper to it so I know it's clean