Keleios

I have a 1996 Jeep Grand Cherokee with 166k miles. Just bought it. Have owned Jeeps all my life, and love them. Will own nothing but. I have never before had this issue with my Jeeps... When I start this one in the morning it turns over great, when I park it at work, work 8 hours she starts great. But if I stop when it's warm somewhere (ie. grocery store to grab milk for 10 mins) when I come out she won't start. She just cranks and crank and cranks but doesn't turn over. I can hear the fuel pump kicking on... If I give it about 10 mins she'll finally start after cranking over and over again.
We did a full tune up - wires/plugs/cap and rotor/coil/oil change all that jazz, but she's still doing this. Runs awesome just when you turn her off when she's warm she won't start back up.
I'm off to AutoZone after work today to buy a thermostat, fuel filter, and fuel pump relay and hopes that solves the problem, but I just don't know.
Can anyone suggest anything to this?

redfox

Sorry if this reply is usless... I am not familiar with jeep but am with general motorhead stuff... (am about to buy my first jeep hence the forum sign up)

Is there a fuel presure switch/ sensor for the injection. If this is fualty when hot it may not be sending the fuel to the injectors, instead it may be releasling the pressure back into the tank or cutting the fuel pump.
Check:- when cold turn the key to on but don't crank. Listen for fuel pump. it should run for a second or two then cut out... now when it is hot do the same. If the pump continues to run then I assume that the pressure is not building to let the injectors work. And that may be an issue with the pressure switch/ sensor... what ever jeep refer to it as..

Hope it helps

Keleios

Yes, thank you so much. Yeah I'm guessing the same as you. I'm going to go through the entire fuel system, starting with the fuel filter, and relay. If that's not it then I'm going to try the Fuel Injector Pressure regulator... then if that's still not the problem, then the damn $300 fuel pump is next... haha just didn't want to get into that much. I want my darn lift kit already lol But thank you so much, and that is essentially the conclusion I have also come to, I was just hoping someone may have a silly suggestion I have yet to try, and hopes that it would get me out cheap and easy. Thanks again.

redfox

P.S. Check all the hoses for the fuel system (including vacuum hoses) for daamage, loose connections etc.
Also make sure the fuel lines are not touching any thing hot! Fuel may evaporate and boil while sitting hot. (most of the fuel lines will be metal and should bend to reposition away from high heat sources)

Keleios

That's awesome advice, and something I have not done yet. Every night when I work on it, it's been dark and I don't have the luxury of a lift or garage lol Thanks again, and hopefully this is something I can go through this weekend. I really hope that that's all it is lol

Keleios

I changed the Crankshaft Position Sensor... so far so good. Haven't had an issue starting her yet. It's been about 3 days, and I've driven it everywhere, starting and stopping when it's warm and haven't yet had an issue Yay! Now let's just wait for something else to go... haha