i have a 93 4.0 and recently it has been randomly dying. most of the time when it dies it is when i am wheeling, sometimes it fires right back up, sometimes i have to wait 10 minutes and it will start. on my way out to a jeep rally today it died 500 yards away from the fair grounds, it wouldnt start at all even after waiting a half hour, i killed my battery and had pops come tow me home, no wheeling today
i have a new fuel pump, filter, pressure regulator, full tank of gas, new ignition coil, cap, rotor, plugs and wires, o2 and tps sensor, and i have to idea whats going on
any help will be appreciated

 

Sounds like your Crank Position Sensor (CPS). Could be other things but that's the most likely cause.

 

I agree with F1Addict. The crank sensor is definitely a primary suspect.

If you buy one, do yourself a favor and buy a Mopar unit directly from Jeep. Aftermarket crank sensors are "hit and miss" with a lot of miss.

 

thanks guys, i will check it out.
if its not the cps could it be a short, or even just a ground that has come loose?

 

Cam sensor in the distributor. My friends 96 did same thing.

 

It absolutely could be a wiring issue. You'll find numerous threads on here discussing refreshing all grounds and electrical connections (I just posted in two of 'em.. too lazy to type it out again, too stubborn to go find them to copy+paste). You could also have a bad relay.

Not sure if the CMP is a factor in the OBD1 Jeeps. On Renix land they will run without 'em, on OBD2 they seem to be as important as the CPS... OBD1 I assume is somewhere in the middle.

+1 Mopar replacement CPS. Some parts you should just replace anyway as they will fail. CPS and exhaust manifold come to mind

 

i finally got to work on the thing today, i checked grounds, fuses, all the obvious stuff. i found that i had a blown ignition fuse mini 15 amp, replaced it, did nothing. started unplugging relays, checking for power to everything, and nothing
i unplugged my cps connector on the back of the manifold and checked for resistance (what Haynes said to do) checked out fine, plugged it back in, pulled some more relays and put them back in and if fired right up.. i think it might have been a dirty cps connector? who knows, but it works now!

i will eventually get a new cps if it acts up again and when i get some money and more time. thanks for the help guys!

 

cps can read good and be bad did u change ur map sensor

 

map sensor can cause the same issue but a cps just goes out there is no warning

 

found the problem. it was a bad ignition coil. i put a new one in about a month ago then i read something about the kind i got going bad really fast which was exactly the problem. so i put a new one in and it works great now. thanks for the help guys!