No power to fuel pump

[secondsupra2004]

I have a service/ diagnostic manual for the MEFI 4 system. In it, it states that when the key is first turned on you should have fuel pump run 2 seconds. The ECM sends a signal directly to the fuel pump relay and then after 2 seconds it does not receive an ignition signal it shuts power to the fuel pump relay. I wouldn’t think that coolant temp sensor or oil pressure sensor would be in that initial 2 second circuit.
I would recheck the fuel pump relay fuse and the relay.

fuel pump circuit photo.jpg
Here is a copy of the circuit diagram. It should be the same as your boat. There is a procedure for diagnosing, but it requires a scan tool. Maybe the schematic can help you at least trace down the circuit. Hopefully there's nothing wrong with your ECM. Thats where the initial signal to the fuel pump relay originates.

[Holdmybeer]

fuel pump circuit photo.jpg
Here is a copy of the circuit diagram. It should be the same as your boat. There is a procedure for diagnosing, but it requires a scan tool. Maybe the schematic can help you at least trace down the circuit. Hopefully there's nothing wrong with your ECM. Thats where the initial signal to the fuel pump relay originates.

Huge help.

What I see here is the ECM is the ground for the fuel pump relay (Dark Green/White) - Check continuity to ground while turning key to "RUN" position. This would assure that ECM is triggering.

Check Pink wire from fuel pump relay fuse with ignition in "RUN" - should have +12V - if not check fuse or connection at fuse block
If the relay is clicking - should be able to feel this also - when switched to "RUN" then control circuit is good.

Another way to check is to test 87A (unused) on the fuel pump relay - it should have +12V at all times unless the ECM is telling the fuel pump to run. After 2sec, this should go back to having power, if the circuit is working correctly.

Not sure where "FROM SYSTEM RELAY" is providing power, but this could be the problem if no power anywhere in this circuit, and fuses are all good.

I know for certain, that the ECM will be in lockout mode and not start the engine for the other sensors I mentioned earlier, but the initial 2 sec run should function every time the key is switched and the gauges go through the reset process.

[HFarr]

Is there by chance another fuse holder that was added anywhere in the circuit? Really does sound like it would end up being something simple like that by how you described it suddenly not working. Of course I guess a failure in the control module could also just suddenly happen too. Double check to make sure it's not a loose connection or corrosion in a fuse holder prior to it reaching the pump. See if there is voltage on either side.

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