1987 F-150 302V8. Engine has only 25,000 miles. Recently started cutting out at highway speed. Won't do it all the time. It seems like electronic problem because if you accelerate, there is no fuel starvation. Tachometer dips about 500 RPM. This chugging is hard on the drive train (Std. Trans.) Ok, here we go....Replaced the plugs, plug wires, cap & rotor, distributor, coil & TPS. Has anyone got any ideas ?

 

Just something to look at...You could have a failing TFI module. However, they normally work or don't work. Since your engine uses Speed Densify EFI, you may have a bad/failing MAP sensor. Being a 1987, you may even have a simple vacuum leak or a mardinal ground connection that is affecting the MAP sensor.