As the title states, 1989 F150 with a 5.8L keeps stalling as I'm driving. It'll lose all power and hesitate a bit then completely stall. When I try to start it just keeps turning over, I can tell it is trying to start but it wont. Then all of a sudden it will start after a few minutes. What I have noticed is that there is a buzz coming from the engine compartment, when I turn the key to the on position, and the buzz is intermittent. When it does not buzz it will not start. It is coming from around where the coil is mounted. I checked the EEC relays, all is well there. Fuel pump, and in tank pump are priming when I turn the key to the "on" position. Fuel filter has recently been replaced. I know the relays are supposed to click, and the fuel pumps are supposed to prime when you turn the key to the on position but whats up with the buzzing? Sounds like some sort of solenoid?

 

Sounds like you have a bad Ignition coil.

 

I forgot to mention I replaced the coil thinking it was the problem, but it still has the same problem .

 

Maybe a failing TFI? Take it off the dizzy, take it to an autoparts store and have them test it over and over again until it's hot and see what happens.

Maybe the ignition switch is taking a dump?

 

Have you pulled the codes yet?

 

Whatever it is, it is related the buzzing noise when I turn the key. When there is no buzz noise it won't start . is the coil supposed to buzz when the key is turned?

 

No it is not.