90 f-150 start/run problem

my sons 150 is starting to give me grief. It will, intermittantly, start then run for 30 seconds, and then die. Will not turn over after dying. But, I can turn it over by arcing the poles on the solenoid. With key in on position, I cant get any spark while arcing solenoid. Any ideas? Thanks in advance, Bob

check the coil, if it's got moisure inside it'll make all kinds of weird problems, also check the distributor for mouisture and corrosion.

well, just my luck, as soon as I read your post, it starts raining enough that I'm not gettin under that hood for a few days, at least, to check out the coil and disty. Too bad too, because my kid cant even roll up the window yet. Will report back when the rain stops and I've had a chance to get back under the hood, Thanks, 2.2, Bob

I have personally seen starter solenoids go bad from oxidation to the point where they will no longer work, if your solenoid is removable remove it and take it apart, there should be some kind of copper disk inside that shorts across the two poles that you arced across.

Take some sand paper or a wire wheel and clean all the oxidation off of it and the back side of the poles if you can get to them, reassemble it and see if the truck starts now, or if you don't want to bother with all this go buy a new starter.

Some solenoids also feed power to the ignition coil during starting and/or after starting, if your solenoid is having a problem it might be why the truck keeps dying.