We purchased a 93 ZJ 4.0 and it has trouble starting and seems to idle ok. Whenever we put a load on it stalls. If we use the electric window it stumbles. Our mechanic has tested the AVR and it comes at 15v+ He is stumped. Can anyone give us some help? I would love to pass your suggestions to our mechanic.

Thanks,

Joah

 

Have you checked plugs and wires? Check the gap on your plugs to make sure it's correct. My plugs were so worn it would hesitate under load.

 

Ok thank you I will let our mechanic know.

 

I know this sounds crazy but I was having some issues with stalling as well. It was very inconsistent. I replaced my fuel pump assembly and cut an access door for future ease of not having to drop the tank. Anyways, after doing a lot of research, in complete desperation, I found a lot of guys with the same issue. Try this, the PCM mounting screws are too long by design flaw. I’ve noticed my dash lights were flickering and dimming at random times as well but that all stopped after I tried this. They end up shorting out the circuit at random times. You should have to either back them out a 1/4”, replace the screws with shorter ones, or cut the existing screws in half. These mounting screws are Torx 15’s I believe. The PCM is located behind the coolant reservoir on the firewall. There will be 3 connectors on the PCM mounting board. Under the very driver side and opposite passenger side connectors is where each screw is located. Backing these screws out halfway sticking out has worked for quite some time. No issues. To get to the passenger side torx screw, remove the 3 bolts securing the coolant reservoir. No need to unplug lines, you’re just going to need access to the passenger side screw and move the coolant reservoir out of the way. There are many forums about ZJs randomly stalling or dying on them while driving. Many have spent a fortune playing musical chairs with parts. Try this and see if it works! After you back the screws out halfway, plug the connector back in and reinstall the bolts for the coolant reservoir.