1990 F150 4X4 will not start
 

My trusted F150 won't start. It worked like a charm one minute, I parked it, turned it off and when I went to take it out again about 10 minutes later, it just wouldn't start. No spark on the coil. I replaced the entire distributor, still won't start. I changed the computer, still won't start. The fuel pump and everything else works, so gotta be electrical. I'm stumped, any ideas as to what might be the problem?

Do you have power getting to the coil through one of the small wires that hooks onto the coil with the ignition switch turned on? Don't forget to turn the ignition switch on.

You replaced the distributor, but did you replace the ignition module that bolts onto the side of the distributor? The ignition module is by far the most common thing to go bad on this vintage of ignition systems.

It could also be the coil itself.

Yes I have power on the coil side with one wire and the ignition switch on. The distributor that I put in there is from my other f150 and it works fine in that truck, it starts no problem, and coil is new. I still don't get a sp

What about the wire that runs from the center of the distributor cap back to the coil? What about the small wire that runs from the coil to the distributor? Did you get the distributor installed in time?

I have a tester on the coil wire. The coil wire I take off one truck, put it on the other truck, the other truck runs. The truck I'm working on has no spark off of that coil wire. The two wires that connect to the bottom of the coil, one of them is red and one is beige. The red wire has power, the beige wire does not have any power even when I crank the engine.

Is the rotor in the distributor properly in place? Is the connection hooked up to the ignition module? Other than that I stumped.

All that is good. I'm stumped too. Thanks very much for the info.

One last thought, does the rotor turn when you crank the engine?

Yes the rotor turns. I tested everything I could think of. If I figure it out, I'll let you know. I would still appreciate feedback from anyone out there, I'm not ready to give up yet. Thanks again.

See where the coil is new - has this been checked?

Suggest the easy button move may be to just swap coils with your running vehicle, or if more ambitious, the primary resistance should be 0.3 - 1.0 ohms, and the secondary resistance (between the high tension post and the (-) terminal) should be 8,000 - 11,500 ohms. If the coil has failed - should see an open circuit (high-high resistance) on one of them.

If nothing else, would eliminate the coil as a possibility...