my 84 d 250 starts up, and 9 out of 10 times everything works relatively fine. the other time it will be hard to start, then it wants to idle wayyy down, barely keeping itself going. usually it will die. if i try and drive it, the lights are dimmer than what is probably legal, and seems to lurch and have minimal power, and will die and backfire.

last night it was doing the 1 out of 10 mode. i was parking it up a steep driveway, so i got a running start (icy) and didnt make it. i rolled back down, and it died halfway...so i started it back up. IMMEDIATELY upon turning the key i knew something was different. the lights were bright, and the truck sounded and ran perfectly from then on.

from my limited mechanical knowledge, i am guessing that the engine is fine, and its not a mechanical problem. its some sensor or wiring, but thats all i can guess at. anyone have a direction to point me to? much appreciated. thanks.

 

I would start at the battery and clean every electrical connection under the hood. Also look for wiring that looks swelled near the ends. Could have corrosion inside the insulation.

 

I'll guess ignition switch. Next time it acts up, shut it down and restart.