Topic: 1995 2.5l yj stalls when hot

[95yjester]

Just like it says, When the engine gets to operating temp on a hot day the engine just dies has happened on the highway and around town.  If I let it sit it will start and run fine for a while until it gets hot again.  I have replaced crank sensor, engine coolant sensor, thermostat. tune up is less than 3k no unusual codes.  Catalytic is not that old. Someone suggested coil could be going bad, also have read about distrbutor issues.

Thoughts please help

[95yjester]

also tested the fuel pressure was right at 32 psi. while running

[grumpygy]

Coil or cat.

[sharpxmen]

you'll need to run some tests when it does that to pinpoint the issue

what codes do you get (you say no unusual codes, do you have a CEL?)
also, how does it die, running on the hwy at speed or when you take it out of gear and foot of the throttle? (does it just go past idle and die or it stops running when you're at hwy speed).
did you test the fuel pressure when was running or when it wasn't starting?
when it doesn't start you need to check if you have spark or signal to the injectors (light bulb test or needle multimeter on volts, should pulsate when cranking). You should also check the ASD (auto-shutdown relay) output and make sure you have 12v when cranking (green/orange wire that goes to every injector and i think same color to the ignition coil). same for fuel pump relay, 12v when cranking.

EDIT: nevermind the question about the fuel pressure (i realized you mentioned it was while running) - you will need to figure out why it stops (spark, fuel or both) and go from there, if its fuel then check the f/p relay, if it is spark then check the coil, plugs, cap, etc, if its both then most likely ASD relay, cam sensor (in the distributor), you mentioned you already replaced the crank sensor, or the least likely would be the PCM but not totally unheard of.

Coil or cat.

imo if it was the cat he'd have some loss of power but should still idle, i had my share of trouble with the cat but was always starting, couldn't drive faster than 20mph one time but as far as starting that wasn't an issue.

[95yjester]

When it dies it is at speed driving,  I can't get it to duplicate in the driveway with the hood open almost like because the hood is open it relieve enough heat to keep it running.  there was no cel, just thought i would check for stored codes.

[sharpxmen]

get a couple of wires out from the ASD relay to the inside of the Jeep connected to 2 light bulbs or LEDs, one wire connected to the command terminal and the other one to the output - if they both die then its an issue with a signal to the PCM or PCM itself, if only the output dies then its the relay. You could also add one to the output of the Fuel pump relay, output dies then its the relay. But you can still test spark when its not starting, if all the rest checks out it's most likely the coil (or you can start with this one). Hard to tell what's going on without codes or any troubleshooting. Since you're not getting any codes i'm guessing coil or one of those relays, if it was a sensor you would most likely have a code but you never know, keep us posted.

[grumpygy]

You are right on the cat Mine felt like it died but kept going at about 20 MPH floored.  I know I was pissed and hoped it would blow.

[sharpxmen]

You are right on the cat Mine felt like it died but kept going at about 20 MPH floored.  I know I was pissed and hoped it would blow.

i stopped at the first hardware store, bought a punch and a hammer and put some holes in the cat right at the inlet, sounded like a tractor but i could get on the hwy and drive it home

it sounded like a turbo though before i put the holes in it, all that hissing sound from exhaust gasses escaping out the joints, it was just the opposit when it came to horsepower

[grumpygy]

i stopped at the first hardware store, bought a punch and a hammer and put some holes in the cat right at the inlet, sounded like a tractor but i could get on the hwy and drive it home

it sounded like a turbo though before i put the holes in it, all that hissing sound from exhaust gasses escaping out the joints, it was just the opposit when it came to horsepower

Had no leaks in mine it went quiet.  Then I would back off and the piece would fall out run good for a mile or 2 and then wam the brakes went back on.  The insides looked like a cigar when it turned right it blocked the exhaust.

[95yjester]

All better, bad coil was the problem!!

Thanks for the help!

 

[grumpygy]

You go with stock I hope.

[sharpxmen]

cool, that was easy - way better than having to replace the PCM

[95yjester]

I pulled the coil out of my brothers early 90's dodge 150 4x4 with a 318 perfect fit same listing for the yj.