I went out to start the jeep the other day and it just cranked over, no start. Didnt have time to fool with it so I drove the truck. Went to see whats going on yesterday and lo and behold, there is no fuel at the rail... I know it has fuel. Heres my question, I can hear the pump running I think. I would think that if its running there would at least be some pressure at the rail? But there isnt any that comes out of the shraeder valve, not a drop. Could the fuel pressure regulator do that?


1994 ZJ 1992 XJ 4.0 motor.

 

It's possible, but the pump puts out 100 psi and if the pressure regulator is stuck open, you should get something in the rail. I'd check the pump relay or lay on your back and have someone turn on the key and listen. It should run for 2 seconds to charge the rail. The pressure may be dying instantly because of an open regulator or open pump check valve, but at least you'd know for sure if it's running or not.

I'd swap the ASD and pump relays. It still won't start but you'll have fuel in the rail if the relay is at fault.

 

thanks, Ill give it a shot tonight.

 

Sounds like the problem I had with the fuel pump on my 2000 4.0 WJ - got in the car, tried to start it - fired briefly then cut out & didn't want to restart.
I could hear the fuel pump running although it was quite noisy but there was no fuel at the rail - had to get the Jeep recovered to my local garage where they replaced the fuel pump - seems the pump impeller had broken off the shaft - at least that is what they told me.