99 XJ 4.0 auto

Here's what happened and I'm not sure what direction to go in....

While driving a back road, she just up and quit. Pulled to the side and it restarted but it was a hard restart. As soon as I gave it some gas it would quit. Went through several cycles of that and gave upon trying to restart. Back in April my coil was replaced (at Jeep with a non Chrysler part). Figured it went south. Replaced that on the side of the road with a new Chrysler coil I bought after the first one died. Fired up easier but still as soon as I got on the gas, it died. I managed to limp home at idle part of the way and the last part of my return trip it allowed me to get on the gas. I made tracks really fast back home.
I'm in a bind as I live out in the sticks with no neighbors to help out. I'm guessing maybe it's the fuel pump, but I'm not sure. I ran a scanner on it and no codes displayed but what was odd was that 3 sensors were in the "not ready" state. This could be a big clue but I don't know which direction I should go int. Any ideas?

I searched but nothing really hit home. I have about 3/4 tank of fuel so I'm not dry.....

Edit: I pulled the cables off and cleaned up the posts as there was a bit of corrosion on them..

 

With no codes, the next step is to test fuel pressure. Must be done with a gauge. For a 99, the fuel pressure spec is 49 psi, plus or minus 5 psi. Many parts stores will rent you this gauge inexpensively and it's very easy to use.

Don't guess. Test. Good luck and keep us updated!

 

The more I read about the issues I'm experiencing, I'm inclined to suspect he CPS. When it crapped out the fuel gauge behaved "weirdly". I let it run at home from a cold start and it started fine and only till it reached operating temp did it just shut down. I'm going to test the CPS tomorrow and if it passes, then it's a fuel pressure test.....

 

Beware that testing of the crank sensor is not always conclusive.

Crank sensor is a possibility, but 10 minutes with a fuel gauge will rule fuel pressure in or out very quickly. As this is a process of elimination, I'd go with fuel first.

If you do end up getting a new crank sensor, do yourself a huge favor and buy a genuine MOPAR unit from Jeep. Aftermarket crank sensors are very "hit and miss", with a whole lot of miss.

 

About 2 years ago I replaced the cps with one from Advanced Auto. It was an emergency situation and I had no choice at the time. If it does prove to be at fault I'll be getting one from Jeep.