I have a 1993 F 150 300 6 cylinder if it sets for at least 30 minutes it seems like all the gas drains back to the tank . I have to leave the switch turned on for about 5 minutes for it to crank
Have you tried a little starting fluid down the intake to see if it starts then? If it does then it is fuel related if it doesn't then it is spark related. On a Ford if the engine fails to start within about 10 to 20 seconds the fuel pump shuts off and won't reset the start mode for about 15 seconds. So letting it sit with the key on won't do a thing with the fuel pump. I am leaning towards a spark problem, has the ignition module or distributor pickup coil ever been replaced? If not, now would be a good time to do so. Don't buy the cheap ones, use a good quality like a NAPA or CarQuest line of products.
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