96 Xj wont start when warm
 

Hi guys,
Im having some problems starting my jeep. It ran fine for about a month after i bought it then i change the thermostat (195) Then she wouldnt start when warm i drove it like that for about a week just wouldnt turn it off until I made it home. I changed the plugs an wires they looked nasty ran like a raped ape but still wouldnt start warm. Did some poking around an found the CPS was junk by unpluging an repluging to get her to start. So i went an got another one when i went to change it i couldnt get the bottom bolt out so i broke it off an installed the new one i got it to sit level by bending the plate a little. It ran awesome for about a week an a half except when it was warm I would have to give it a little gas while starting. Then the taillights went out so I only drove it around the yard, fixed the tail an now it wont start when its warm. It will crank an crank unless you push the gas pedal to the floor!! But when its cold it fires right up with not 1 problem, Im completely lost an low on cash because it did this right after I got new 31's BFGs.

The current problem is wont start when warm it will crank unless givin gas an then after that it wont idle on its own it dies as soon as I let off the gas. I checked fro spark its good, i checked for fuel i seem to have but dont have a fuel pressure gauge. I checked the Cel an it throws 2 codes 1 is the coolant sensor an i cant count the second one right for some reason. I hope this is enough information, Thanks is advance guys :thumbup1:

Btw I have searched an searched I need help!

I had a Ford vehicle that did exactly as you describe. It was the coolant temperature sensor. Should be cheap to replace. NOT the sending unit one that shows your temperature on your dash gauge, but the other one that actually gets the temperature for your Jeep to run.

Thank you, im going to figure out where its located an take a look maybe get a ohm meter tomorrow

1. We need ALL codes. The codes are the absolute bible to guide you to a fix here. Give us the exact codes, not a description. With a 96, it's best if you can get a code reader or a scan tool to read the codes. The codes you get with those tools are much more valuable to you than the 2 digit code you can get on your own. The POXXX code is much more specific.

2. That crank sensor is still a wildcard here. If "spacing" is off a little and you have a thermal (heat related) failure, it may be related to the mod you made.

Yeah after i get the part tomorrow an install it I'm going to take it to Autozone they will hook it to the computer for free.... just couldnt make it there till tonight an by then its to late, An i belive your right on the CPS thats why you have to give it gas to start it. I will post the codes tomorrow. Thanks fellow Cherokees friends

My money is on P0128 - Thermostat voltage threshold, basically a rationality code.

ORRR... could be a hairline crack in the ignition coil. When it warms up it expands, and won't fire.

Just my $0.02. I've had both several times over the years.

^^How do i go about checking this??^^

check codes with key on key off method have you tried this yet

I also have the same problem in a 96 XJ too. Yet to find the culprit. Ill keep an eye on this thread, and maybe well figure it out!!!!

Yes, I did the key trick thats how I figured it out it was a Coolant Temp Sensor. But i unpluged it last night an drove the ole girl about 20 miles in the little snow storm we had here. I dont not have one idle problem..!

LaxBro whats up with yours?