Toyota Repair: 1991 Toyota Previa SE, fuel pressure gauge, long trip home

Question
QUESTION: I am having problem with the engine just shutting down with little warning.Starts after driving for 60 or 70 miles and then starts bucking like I'm running out of gas.1st diagnosed as a problem in the Mas Airflow Meter which was replaced solving the bucking problem but not the engine shutting down.I have replaced the rotor,distributor cap,and plug wires.fuel pump pressure checked good.Van has 22,500 original miles.Manual said to check EFI Main Relay but unable to locate where manual states in dash.I've had this vehicle to the Toyota dealer and they have not been able to find the problem.Could the fuel pump be breaking down when it gets hot.I would appreciate anything that you can suggest.Thanks

ANSWER: The EFI main relay is located under the dash on the left, I can send an illustration that may help locate it, please reply to tedrttr@yahoo.com

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QUESTION: I read your answers to similar problems on other Toyota's about the engine just dying at any speed.The last time it happened to me at 70 on the interstate and did restart after several tries but would cut of again after several miles and restart making for a long trip home.I stopped for several hours to let it cool down and it would be fine for awhile but started over again.Should I replace the coil/distributor, EFI Relay, etc.Any suggestions or directives would be appreciated.Thans againg for helping me and all the others.

Answer
Has the fuel filter been replaced, if not it may be worth a try, could the fuel pump have this intermittent condition? Yes, the best way to check that is to connect the fuel pressure gauge with a hose long enough so the gauge can ge read from the inside, then check the pressure when the stalling condition occurs.