1998 xj 4.0, was driving, sputtered & shut off. How can i tell if its the fuel pump, relay or fuse-what & where to check

 

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!

 

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!

 

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

 

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.