Obd1 cherokee misfire
 

This issue arose recently . I'm having a noticeable random misfire . I've noticed my 94xj taking a bit longer to start initially after sitting overnight . Don't always hear the fuel pump prime as I key on like I used to. On a 20 minute drive I average a handful of misfires throughout the trip . Doesn't matter if off idle or doing 75mph. It feels like you kill the ign for a split second , it will just give you a quick buck but it's extremely quick but noticeable . So far I've changed the plugs, swapped the fuel pump, swapped the fuel pump relay , opened up all the sensor plugs to check for moisture or corrosion. It throws no codes. Next is a new cap /rotor . It idles beautiful and makes good smooth power besides this random issue. Any ideas? Thank you!

Finish the tuneup and then see where you are at.

Still need new plug wires, cap, rotor, fuel filter. All money well spent.

The importance of fresh tuneup hardware cannot be overstated.

So I swapped out my crank sensor and took it for a ride and it seemed good, no issues. Hope it stays like that.

On the other hand the fuel pump is not priming sometimes on initial start after sitting. If I turn the key I won't hear the pump run and if I keep cranking it won't fire. I then cycle the key and hear the pump prime and it fires right up. What powers the pump when you key on? I'm trying to track down why its intermittent . It never use to do this

Obd1 cherokee misfire
 

Could be a sticky relay in the engine compartment. I don't know what one it is but it should be labeled somewhere.

Read post 2 again...

It was my pcm. My check engine light wasn't coming on . Lazy pcm. I fixed it for 5$ by soldering in new capacitors