Just picked up a 1990 f250 with a 351w. I test drove it and it ran fine, drove it home (about 35 miles). When I drove it next it started up and ran fine, tried to start it again but it just kept trying to crank but nothing. Hooked up a spark tester and tried cranking it, nothing happened until I turned the key back. I replaced the ignition coil and still doing the same thing. Maybe a relay problem? It seems like something gets hot and it doesn't wanna start. Any help? I'd appreciate it greatly.

 

Is this fuel injected? If so I would pull the codes and see what you get. Here's a site that tells you how to do it. Ford Fuel Injection. If you just want to throw parts at it, and you didn't have spark, I would replace the ignition module.

 

Alright thanks, I'll try to pull some codes and see what that tells me.

 

what do you mean"nothing happeneduntili turned the key back"?............maybe it is your ignition switch?

 

It tried to start but no spark until I turned the key back, as if it were discharging or something

 

It turned out to be the EEC:[ I finally had to take it to a shop..