96 Engine Stops Running - Fuel Pump

I am definitely not a mechanic and only have novice experience with an XJ. My son recently purchased a 96, 4.0, 4WD that sometimes stops running after 40-50 miles or so then won't start. It runs very well up until then. Let it cool off and it will start right back up and run for a while again. It seems like it is getting no fuel. I've replaced the cam and crank position sensors (probably needed to do that regardless) and plan to run it later today to see if it dies again. We are going to check fuel pressure today after it cranks and after it dies if it does so. BTW it doesn't throw an error code and only had an old error in memory for a catalytic converter, which was replaced not very long ago by the looks of it.

If I should have to replace the fuel pump what brand is recommended to use? I know there are some cheap brands but I prefer to stay away from those and would rather get a quality replacement.

On my '96 the fuel pump got very loud and still kept working. I was told to turn up the radio to cover the noise.
Also fuel pumps for the '96 are unique to that year and can be quite pricy.

It might be your CPS (crank position sensor) going out with thermal failure.
On our '89 (you can't have just one . . ) the CPS would heat up the engine would die.
I tested it by using a long funnel, pouring some water and cooling it down, engine would start right up until the CPS heated back up.

Hope this helps,
Mike

Bosch seems to be a good unit for the fuel pump itself, but taking the time to diagnose the problem is best, and it sounds like you are going that route.

If it turns out to be the pump you probably have two routes you can take. I think the complete pump/sending unit assembly can indeed be ordered, but expect to wait a while for it. Alternatively you can replace the pump and pressure regulator on your existing assembly. I do recommend doing both as it seems one of the more common failure modes is the loss of the check valve feature in the tank.

I have done a write up on the '96 fuel pump and pressure regulator replacement: http://www.naxja.org/forum/showthread.php?t=1107991&highlight=1996+fuel+pump

If it turns out to be the CPS you can find plenty of info on here for that as well. From underneath with about 36" worth of extensions seems to be the preferred method, but someone found that from up top with a crow's foot works too.

I had the same symptoms when my cps went out