Need Help Stranded 88 Cherekee

I show alot of care to this vehicle i took it for inspection ahead of time because i done so much. It passed with just a coule of leaks i needed to fix ex. oil pan gasket, auto trans gasket( i did already), power steering box, and pump, and hose, i have the power steering box i want to put it in but all of a sudden my jeep wont stay on the last thing i did was change the spark plugs one at a time drove to get my kids right after then left the car parked and now i can start the car but it turns off immediately, now, not all the time but sometimes i can turn the key all the way on(cranking) for couple of seconds and the car will stay on but if i shut it off i cant start it up without it shutting of please tell me whats wrong if u need to ko what i change i'll be glad to let you know

by the way its a straight 6 4.o l 4wd

Possibly the problem lies in the ignition switch. Pay close attention to when it shuts off and where your key position is at. If it has high milage, then a worn switch is probable. Also double check your vac lines, especially the one running to the vapor canister, on the same side that the plugs are on. Just make sure you didn't accidently knock a hose off.

Possibly the problem lies in the ignition switch. Pay close attention to when it shuts off and where your key position is at. If it has high milage, then a worn switch is probable. Also double check your vac lines, especially the one running to the vapor canister, on the same side that the plugs are on. Just make sure you didn't accidently knock a hose off.

sorry i never updated it was the ballast resistor on the driver side firewall
I just bypassed it!!