Odd ignition problem

Ibby

I had a bit of an interesting problem with my CJ today. I'd put the key in and it would turn over and start up fine, but when I released the key after starting the engine would stop. After a few tries and a bit of cursing it started fine and kept running so I kept driving around. I stopped for about a half hour, and the same thing happened, it would start but shut down after releasing the key. Again after more cursing it started, but I noticed the voltage was low. I managed to make it home on reserve well enough (Optima batteries rule!) and swapped out the alternator with a spare. The voltage is proper now, and the Jeep seems to start up well enough, but I'm just wondering would the faulty alternator cause the original problem with starting/running? It's got a 304 in it, and a Painless wiring harness about 2 years old so I know all the wiring, grounds etc. are all good. Any ideas?

ironman_gq

sounds like your ignition switch could be going. its not keeping contact with the ignition circuit when it transitions from start to run. Check all connections and the ignition switch

Ibby

Finally found my problem tonight! I had checked the switch, it seemed ok. I ordered a new one anyway since the one in the Jeep was 30 years old. Still had the same problem. So I figured the "run" side of the Duraspark module was bad. I'm out of spares so I ordered an MSD 6a and happily installed it. The 6 foot magnetic pickup extension was wired backwards. I got a few miles out of it and poof! All the smoke got out. Tonight I found an HEI distributor I had forgotten about so I wired up the module using the same pickup from the MSD kit. It ran but sounded terrible. I rechecked everything (again) and discovered to polarity problem. After that, it fired up in "start" but shut off in "run" just like before. I ran power through a switch to coil + and it worked fine. And I heard a relay click under the dash. Turns out the Painless kit I installed had corroded quite a bit, to the point that some contacts were just green dust. That'll teach me to run with no fenderwells in the winter. Pretty good learning experience though, after Googling up a few other well known Jeep sites I know a ton more about ignition systems than I ever thought I would.

rollen dean montoya

at least ya got it fixed and didn't burn the jeep up.

ironman_gq

thats the beauty of road salt :(: It can turn the best things into piles of corroded dust in record time.

ol' school power

ironman_gq wrote
thats the beauty of road salt 🙁: It can turn the best things into piles of corroded dust in record time.

Silicone dielectric grease (available in tubes from your favorite parts store) inside the connectors before you plug them together keeps them from going to dust.

Ibby

I greased the hell out of it. But since the fuse box sits on the firewall right behind the tire, and since I have no inner fenders, only homemade flattys, the tire tends to sandblast road salt right into the connectors. I'll be taking care of that shortly though. I'm getting tired of cleaning and greasing my connections every month or two during the winter here.

ol' school power

Ibby wrote
I greased the hell out of it. But since the fuse box sits on the firewall right behind the tire, and since I have no inner fenders, only homemade flattys, the tire tends to sandblast road salt right into the connectors. I'll be taking care of that shortly though. I'm getting tired of cleaning and greasing my connections every month or two during the winter here.

Weathertite connectors