Nissan Repair: Fuel Pump Relay Switch, oil pressure switch, fuel pump relay switch

Question
Hi Von,
Okay we have replaced the relay switch, and still having problems, what and where is the ECI I hope that is right, my 1986 300zx non turbo it starts up right on a dime but can not seem to keep the fuel pump from shutting off and sometimes we have to turn off the key turn it back on to finally get the fuel pump to come on. Thanks so much for all your help
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Followup To

Question -
Hi Von,
Okay this is it short and sweet. I have a 1986 300ZX non Turbo, started fine when I bought it and drove it home, now it will start but will only run for a few seconds, sounds like the fuel pump goes off after a min or two is there a relay switch or reset switch that can be reset? I would be soo grateful for any help you can give me. Thanks, Laura

Answer -
Laura,

The relay is for th epump to stay on as long as the key is on.  If the pump is shutting off the relay is going out or the pump is overheating.  You can turn the key on without starting the engine and get a test light to check current to the pump.  If the power shuts off replace the relay.  If the power is constant and the pressure drops off replace the pump.

Answer
Laura,

If the ecm, located behind the center console, is turning off the pump.  I think your oil pressure switch is defective and not sending the pressure signal to the ecu and that causes the computer to turn the pump off.  If your pressure is good it is the pressure switch.  If this does not do it wire around the problem from the relay to switched ignition.