97 XJ question!!

What would make my fuel pump intermittently not come on when I turn the key? Sometimes I turn the key and I can hear it kick on and somestimes it doesn't when I turn the key.

-has a new CPS
-runs great after it does kick on and start
-cranks over great
-checked relays
-checked fuses
-NSS is cleaned and works
-isn't throwing any codes

Anybody come across this with their rigs before? I hate electrical gremlins!! I didn't see anything while searching that had the same issue. thanks for any info!

Try bypassing the ballast resistor mounted on the drivers side fender under the hood. It's the big white block with two wires in it just unplug them and put them together. I've seen others with that resistor go out and cause similar problems, all it's there for is to cut down on the noise from the filter so it'll just make it a little louder.

The ballast resistor was eliminated in 94.

On both of my 96's, the connector for the fuel pump needed to be cleaned and dielectric grease put into them. They would work intermittantly, but both were fixed with the connector cleaning. Not sure if they are the same, but its worth a check.

~James

Thanks for the info so far! I checked, cleaned and used dielectric grease on the connection. It was clean inside though.

I have a new symptom I was driving across the base and I went to pull in a parking spot and it just shut off. I turned the key to the on position and no fuel pump! I did this 14 more times and on the 15th try the fuel pump kicked on. So I parked my rig, shut it off, turned the key to the on position and no fuel pump again. I tried this a few more times and then the fuel pump kicked on again. Is my fuel pump just going out or is this a symptom of something else?

Carman

Try swapping your relays around, the ASD relay may be failing.

I bypased my fuel pump relay and it runs constant, repeatedly with the ASD relay jumped out also so I have to say the pump is good. I recently replaced both the fuel pump relay and the ASD relay but it looks like it or they maybe an issue. So I just ordered 6 new relays to replace what I have under the hood with a couple spares.

Does anybody have any other ideas that might cause the relays to go bad? Maybe I have an underlying problem I just don't know about yet!!

Is there any possibility that when I replaced my CPS that it is sitting further away from the flywheel or that the flywheel maybe dirty enough to mess up the signal to the CPS??

Carman

When you turn the key to the ON position the ASD relay is going to provide power to the fuel pump for 3 seconds. If you aren't getting that "prime" of the pump I'm pretty sure your problem is not CPS/CKP related.

Yeah I'm thinking the same thing right now. I was just wondering if that would just randomly shut down my rig. I know that what it is supposed to do but what would make it switch to shut down for no reason? I hope it is that simple! Relays are cheap but I curious if there might be something else. I REALLY, REALLY don't like electrical issues!!!

The ASD (auto-shut down) relay will kill your engine. I would replace the relay and then hit all the connectors with some cleaner and dielectric grease and see if that knocks the problem down.