1996 F150 4X4 302 - I changed the Ingnition control module, distributor cap, rotor, wires and plugs but my problem will not go away. The truck starts up everyday the first time I try it. After a few minutes I turn it off and it will not start again. It cranks strong but will not fire up. I am getting spark at the coil and the plugs and there is fuel pressure in the lines (tested by opening the fuel rail relief valve). THEN If I let the truck sit for an hour or so It will start right up again with no problem until I turn it off. What am I missing? What should i be looking for? Could the fuel filter be causing this? (a desperate guess). Thank you

 

Are the plugs wet when it won't start?

 

This might have nothing to do with your cit. but I have an explorer with the v8 and it did the same thing and the cat converter was plugged. The easy way I found out was that the cat was glowing red at night after about 5-10 minutes of running.

 

There are two stratigies used.
The cold start fuel is controlled by the ECT and the ACT.
After about 45 sec to a min. the EEC transfers to closed loop to control the fuel.
Be sure the ECT and ACT connectors are no corroded.
Sounds like the closed loop operation is in fault.
Test for fuel pressure with a gauge. Just opening the test port is not good enough. Your testing for 39 psi.
Next scan for any stored codes.
There are several areas that could cause the problem.
The PIP in the dist may fail when hot. This sensor detects a moving dist and in turn tells the EEC so it can fire the injection and the ignition.
The injection is fired 4 injectors at a time. No injection no run!.
Of courses it can be some other fault that is related like the cable plugs between the EEC and the injection/ignition control etc.
Good luck.