Fuel pump or?
#2
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Year: 1999
Model: Cherokee
Engine: 4.0
It could be fuel. But it could also be spark. Don't assume anything.
I always test for spark first. Pull a plug, keep it attached to the plug wire, place the plug electrode near a good engine ground. Have a buddy crank the engine over while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white indicates a weak spark which may not be strong enough to start the engine.
If you have good spark (and only if), then introduce a little bit of gas or starting fluid into the intake. If the engine starts and runs for a few seconds, you have clearly identified a fuel delivery problem.
Also, when you turn your key to the ON position, the fuel pump should energize and run for approximately 2 seconds by design, then turn off.
The above are quick and dirty things that go a long ways in determining root cause of any "no-start". Good luck and keep us posted!
I always test for spark first. Pull a plug, keep it attached to the plug wire, place the plug electrode near a good engine ground. Have a buddy crank the engine over while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white indicates a weak spark which may not be strong enough to start the engine.
If you have good spark (and only if), then introduce a little bit of gas or starting fluid into the intake. If the engine starts and runs for a few seconds, you have clearly identified a fuel delivery problem.
Also, when you turn your key to the ON position, the fuel pump should energize and run for approximately 2 seconds by design, then turn off.
The above are quick and dirty things that go a long ways in determining root cause of any "no-start". Good luck and keep us posted!
#3
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Year: 1998
Model: Cherokee
Engine: 4.0
The first step is to see if the problem is fuel- or ignition-related. Do a quick check for spark while cranking, and if you have a strong spark, put a fuel pressure gauge on it and see what you get.
Edit: Treed by tjwalker!
Edit: Treed by tjwalker!
#4
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Year: 1999
Model: Cherokee
Engine: 4.0
In addition to the advice tjwalker gave you, you can do a quick fuse check in the PDC. See pic.
Check fuses marked Fuel Injectors/Coil, ASD, and Fuel Pump PCM
Check fuses marked Fuel Injectors/Coil, ASD, and Fuel Pump PCM
#5
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Year: 1998
Model: Cherokee
Engine: 4.0
I'm almost as smart as you guys. Spark was fine, pulled air cleaner from injector/intake-bone dry. Starting fluid fired it right up. Where it died, it was too noisy & i couldn't hear the pump. After i towed it home, no, the pump wasn't turning on & of course the tank was full. While getting everything underneath the tank to drop it, i saw a wire dangling. Hmmmmmm....yup, cut the rusted, rotted endsoff, reattached it & i heard the click & buzz of the fuel pump. Started right up.
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