Hi to all, I write from italy, excuse for my english, and please place the reply in easy language.....
My '90 xj 4.0 automatic transmission isn't no so popular here, (typical diesel engine).
Frome some week I've this problem: the engine suddenly switch off. cap & rotor, sparks plugs, sparks plugs cables are new. If I wait 10 minutes (more or less) and re try switch on the car may be run but after some miles, switch off again....
The problem before aren't frequent, now it's very frequently. Help-me please. Where I start to check?
Thanks to all in advance.
steve.

 

Check the wiring all the connections that you can find and start with your ground wires, clean where they ground to the truck(needs to be tight against bare metal)

 

Thanks for very fast reply, but I've do it the check that U hint the last week end, and I've clean the connector with spray....

 

check for a short in the ignition key switch

does everything shut off like your radio and lights or just the motor?

 

...just engine....

 

Fuel pump...could be getting hot, and shutting off.

 

How I can check the fuel pump?

 

thats what I think also

you need to have it tested talk to your local auto parts store they may be able to rent you a fuel pressure tester

 

possibly the cps?

 

did this guy say his xj had a diesal? And then go on to talk about the spark plug wires?

 

He said his 4.0 is not as popular as the diesel...

 

Check the CPS connection. Clean as well as possible and use dielectric grease on it. It only takes a small bit of resistance to disable the engine from running. The voltage going through those wires are very low. (+/- 5V)

 

I have a question for you when you say that the jeep switchs off, does it start right back up for you or does it just crank/ turn over.

If it doesnt start right back up then i would say check to see if you hear the fuel pump turn on when you move the key to on have somebody turn the jeep on while listening to the fuel pump in the tank.

If it does start right back up then i would check you CPS like suggested.

 

thanks to all, today I try... and post the result.....