I own a 98 Jeep Grand Cherokee Limited, has over 200k miles on it. The other day we got our gas siphoned out to where I had enough gas to start it up and reverse out of my parking spot. It suddenly died without a sound or warning before I was even able to put it in drive. We put more gas into the tank, we can hear the fuel pump working, the line going to the engine has gas coming out so we know it is reaching the engine. We just changed the distributor cap and the battery is good but it still only turns over but wont start. All the wires are on tight, could it be the starter?

 

Start at the cheapest possible solution, check all fuses and relays. Once they have checked out as good it is time ot start checking other things.

I know that a certain fuel pressure is needed to for the engine to run, but I can not remember off hand what that pressure is. Even though you can hear the pump running it may not be able to supply enough pressure. Also check to see if you have spark. Even if you changed the cap and the wires are on properly there is still a chance that you are not getting any spark at the plugs.

I will be honest, it really sounds like a no spark issue to me. It turns over but wont start, only two reasons for that. Something is keeping it from sparking, or it isn't getting any fuel.

 

Welcome to CF!

I'm betting it has something to do with the security system. If it's turning over, it's not the starter.

All I know about the security system is the engine function part. The PCM has to get a signal from the CPS within 30 seconds or it will not pull in the ASD relay and allow spark or injectors to work. You can substitute a headlight relay for the ASD relay to see if the relay itself is at fault. The ASD relay probably shut down the engine when the loss of fuel pressure happened. When you switch the relays, turn on the headlights to see if the ASD relay works for the lights. If not, there's your problem.

BTW, the fuel pressure should be around 45 to 50 psi. The earlier models should be about 37 psi. You can rent/borrow a gauge that screws into the fuel rail test port.

 

I will check those out in the next day or so and let you know how it turned out. I just hope its an easy cheap fix since we are low on cash and its our only vehicle.

 

It wasn't the security system, replaced the coil pack and it sounded better while turning over but still a no go.

 

I just want to say this and try not to be insulted Test before replacing anything. Throwing parts at a problem before finding the source gets real expensive real fast. If I had just went ahead and started throwing parts at my last electrical problem I would still be replacing parts. It turned out that all I needed to replace was a fuse and fuel pump connector, and the PCM thanks to the previous owner jumping the blown fuel pump fuse

Also if you replace a bad part, but don't find the reason it went bad, that new part could be bad sooner than you like

 

Well said, SG!