Dshuster

I have an 89 jeep Cherokee limited. It recently stopped running and we thought it was a fuel problem so we changed the fuel pump and fuel filter. It now runs for 6 or 7 seconds but then it cuts out and spits and sputters and when I give it gas it dies. Any got an idea of what it might be??

F1Addict

So it probably wasn't fuel related. You can rent a fuel pressure gauge from many larger chain stores. Screw that bad boy onto the fuel rail Schrader valve and see what you've got! There are several things that could be causing your problem (IAC, TPS, CPS, vacuum leak, etc.). Is there anything else we need to know? Did you pressure wash (or just regular wash) your engine, by chance? What symptoms led you to this diagnosis?

Dshuster

I have not washed it. But I have hooked a fuel pressure gauge up before and after the new pump. When the old pump was on it ran low pressure but then dropped. With the new pump it runs the right amount of pressure at first but then it slowly drops until it dies

F1Addict

Someone else will have to concur but the only things I can think of are...

1) Clogged or otherwise failing fuel pressure regulator
2) Improperly installed fuel filter (unlikely)
3) Clogged or crushed fuel line
4) Crappy/defective fuel pump. It's not, by chance, an Airtex, is it?

Knowing how this started would be helpful. Was it running perfectly then just randomly died while driving? Was it running perfectly then wouldn't start the next morning?

Dshuster

It had been spitting and sputtering for about 2 weeks but that was only when I went to take off or when it was idling. It would die sometimes but would start right back up. It would run fine after I got moving and kept steady throttle. It just died when I was driving and it would start but would die after 2 or 3 seconds

Crazy 8s

This sounds like an issue I had the other day. There is a ceramic resistor on the left front fender by the airbox that limits power to the fuel pump. If that resistor is defective or not plugged in the motor will start and run for a couple seconds and then quit. Look into that in your troubleshooting... You can run a jumper from one connector to the other side and bypass that resistor. If it fixes it, then you know what to replace... If not, then one part you've eliminated from the list of steps.

F1Addict

That sounds very much like the Crank Position Sensor (CPS) but I would check the ballast resistor mentioned by Crazy 8s, as well. You can test your CPS using the tips found in member Cruiser54's signature.