Chevrolet Repair: Fuel pump wont prime, oil pressure switch, wire connections

Question
I'm working on an 87 S10 2.8 auto trans with fuel injection. I have to turn the motor over 4 times before the fuel pump in the tank will prime the injectors. I have jumped the connector at the oil pressure swich and the pump runs with the ignition off. What's the problem. Thanks, Roger

Answer
HELLO ROGER,
THE FUEL PUMP IS OPERATED BY A RELAY WHEN THE SWITCH IS TURNED TO RUN. THE RELAY ENERGIZES FOR THREE SECONDS, UNLESS IT IS RECIEVING A CRANK SIGNAL, IN WHICH CASE IT IS SUPPOSED TO STAY ENERGIZED AS LONG AS IT IS GETTING THE SIGNAL.
AS A REDUNDENT SYSTEM, THERE IS AN OIL PRESSURE SWITCH THAT CLOSES AND SENDS POWER TO THE PUMP, WEATHER THE RELAY IS WORKING OR NOT.
SOUNDS LIKE YOUR OIL PRESSURE IS DOING IT ALL. CHECK THE RELAY, AND POSSIBLY THE ECM. WIRE CONNECTIONS ARE ALSO A POSSIBILITY.
GOOD LUCK,
VAN