The truck shuts down?

I have a 1988 Ford F250 4x4 4.9 Liter Straight 6

This started about a month ago when the weather started to get warmer. The truck starts up fine will drive for about 10 to 15 minutes then stall out; if I wait for about 1 hour it starts right back up runs fine for about the same length of time then shuts down. It’s been in the shop four times now, here is a list of parts that have been changed:

Radiator

Thermostat

Fan Clutch

Ditributor (plus pick up)

Distributor Cap

Rotor

Ignition Module (located on distributor)

Plugs

Plug wires

High Pressure Fuel Pump

Low Pressure Fuel Pump (in tank)

Fuel Filters

Fuel Relay

EGR Relay

Some wire pig tails

After replacing all of these it still does the same thing, but the engine runs real well until it shuts down.

Last week when it shut down I pulled a plug wire put a spare plug in the wire and had my wife try to start the truck, it looked as if it was getting good spark.

Any Ideals?

Thanks

I’m not sure if your model of Ford truck has it or not but check your owners manual for an “inertia switch”. It shuts off power to your fuel pump in case of a collision. My uncle had a bad one in his Ranger pickup. It would shut off the fuel pump at various times and he never had a wreck. The switches just become intermittent. Note: It was well hidden and was on the passenger side…under the dash…under the carpet which was on the opposite side of where it was supposed to be.