Jeep Fires But Won't Run

Well I'm back into jeep mode and I've already got a head scratcher. Yesterday I took my jeep for the first big ride of the season to shake out whatever problems needed addressing before putting it to use all winter, and a few things revealed themselves including one problem I can't wrap my head around.

For starters my battery was low (pretty sure the alternator isn't charging) so I got one good crank out of it, took a ride, and came back to a dead battery and couldn't get started. I jumped off to another battery and at this point the jeep would fire but wouldn't stay running. I was a little low on gas at the time so I went ahead and put another gallon in there just to make sure it wasn't a fuel problem, but still the same result. I had this problem or at least a similar problem two years ago when the ignition wire from the distributor to the key cluster broke off. I was able to chase that down and replace the wire, but that doesn't look like the culprit this time.

I'm wondering what other things I can check for other than the ignition wire. I have a mechanical fuel pump as well as an electric pump wired to a switch. I tried running the electric pump simultaneously just in case it was a fuel pressure problem but no luck. The spark plugs and wires are less than 3 years old but I guess it'd be worth checking. I have an HEI distributor... Just trying to think here... Any help is appreciated. Thanks!

-Henri

 

Does it "fire" while cranking, but die immediately when the key is returned to the "run" position? Ballast resistor burnt out or a fault in the key-switch or that circuit, if you jeep has one.

 

Yes it dies as soon a the key returns to the run position.

 

It has fresh gas, good thought though thanks

 

What Pete wrote. The ignition switch bypasses the "run" circuit when you turn it to start. When the switch returns from start to run, that circuit is open and the engine dies. Hot wire it, and see if it keeps running. Then look critically at the ignition switch, starter solenoid and connecting wiring. Most likely a bad ignition switch.

 

Thanks, I'll take a closer look at that circuit and see what I come up with!

 

Had similar symptoms on my CJ5 and in that case it was indeed the switch.

Walcks has one that actually fits a CJ5. Most other suppliers sell a generic switch they list for a CJ5 which will fit the smaller hole in a CJ2A dash, but does not fit well in the CJ5 dash without a spacer.

 

Problem solved sorry to say it was pretty basic! The key cluster was getting loose so it rotated as I turned the key, which broke the connector to the run wire. This jeep stays about an hour and half away from my house in the winter so whenever I have a problem I always end up overthinking things because it's a long way back to the house if I don't have the tools I need! This time it was simple at least.

 

Exactly why I bought a switch that fits.