It is wrong.
Either the ECM via it's fuel pump relay, OR the oil pressure switch can supply power to the fuel pump.
If either is on, the fuel pump gets power. If both are on the fuel pump gets power.
The ECM activates the fuel pump relay for two seconds when the key is switched on. It also keeps the fuel pump relay activated anytime it sees ignition pulses, and for two seconds after the last pulse. Anytime the fuel pump relay is activated, the fuel pump should be getting power.
The oil pressure switch sends power to the fuel pump any time there is oil pressure. So on a cold engine, that is from when you start cranking it to up o 15 seconds after you turn the key off. On a warm engine the oil pressure will drop much quicker.
Either of these things can/will supply power to your fuel pump.

| quote | Originally posted by lurtz:
Take this for what it is worth because I am not a mechanic, but you say it will start and run for ten seconds then die. Could this be the oil pressure switch? Once the ECM recognizes the car has started the fuel pump is switched through the oil pressure switch. If the switch is faulty and not sending a good signal this could shut the fuel pump off and kill the engine. Again I am not a mechanic so please anyone if I am way out in left field please speak up.
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