Hi yall. I dont normally come down here to the gas burner fourms but I figure Id give it try in hopes that someone could help me. Ive got an 88 Ford F150 with the 5.0 EFI motor and the sob has been giving me some serious problems lately. The truck will start fine and run great when its cold, but as soon as I get a few miles from the house and the truck gets warm, it will sputter and eventually die. I have to wait 20 or 30 minutes for it to cool down. In the mean time, while Im sitting on the side of the road, it will crank just fine but it gets no fuel at all, no pressure whatsoever, just air. I have checked this by putting a pressure gauge on the schraider valve. Once the truck is cool again, it will start and run fine. I have recently replaced the tps, front tank fuel pump, fuel filter, and a while ago the fuel pump relay. What do you all think is going on? Thanks in advance.

 

What about the pump on the driverside frame rail have you replaced that?
When you turn the ignition key to run you should beable to here that pump run for 2 seconds.

Each tank has a intank pump in addition to the one on the frame rail

Here's a pic. of the frame rail pump. There's a small pig tail harness that splits into two individual push on connectors at the pump. One connector for 12 volts, the other for ground. The push on connectors can come loose.

 

No I havent replaced that yet, though I do hear it running for a breif period when the key is turned to the on position. Have checked all pump conections and they are tight and clean

 

Could be the TFI(?) module that is located on the side of the distributor.
These fail quite a bit 'cause they get so hot.