Ford Repair: Engine not getting fuel, fuel pressure guage, fuel pressure regulator

Question
Hello Mark,
  My 1994 Ford Ranger has been giving me intermitant failures, over the past year.   Where I've come to learn that when it fails ( won't start or sometimes just like turning the key off while driving down the road ), the engine stops getting gasoline.
 So far I've replaced the fuel filter, fuel pump relay, and the fuel pressure regulator.  I bought a fuel pressure guage today, and when on Run, the fuel rail is stable at 40 psi.  Spec is from 35 to 45 psi.  The pump continues to run, even though this pressure as been established.  Where under normal conditions, the pump comes on for 3-4 seconds and shuts off, until the ignition is put to engage the starter.
 What controls the pump to shut off after presurization ?
Or is it just a time out in one of the control modules ?
( PCM, EEC, etc. )  If it's a time out only of the control modules, does this flag to the relay have to happen, before the injector signal goes out to the injectors ??
What wire ( color coded ) goes to the fuel relay, to turn it off after initial presurization ?  Maybe I have a bad wire ?   Note, over the course of the past year the dealership says they have replaced the EEC module and the Ignition Module, along with the Ignition Switch in the column.


Answer
ok normal operation of the pump is-

when you turn key on pump comes on to pressurize system when turn key to start position pump comes on again and hopefully engine starts-after engine starts pump continues to run and can put out pressures as high as 100psi or more-what controls the pressure is the regulator opens at 40psi-or whatever spec is on your engine and excess fuel is returned to the tank via a return line-this continuous flow of gas is what helps cool the pump also that is why restricted filters burn up pumps.

so yours is working normal from what i see so far-next time your truck quits and won't restart you need to check pressure then-if pump is coming on but pressure is low you probably have a bad pump-if it won't come on at all you have to start checking to see if you have power to the pump and ground if so then you have a bad pump-good luck