454 MPI Fuel Pump Issues, Pump not getting power
04-21-2013, 08:27 PM
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454 MPI Fuel Pump Issues, Pump not getting power
I have a 1999 Powerquest 22ft with a mercruiser 454 MPI with a Braveo 1 drive. The Fuel Pump is not getting power, causing the engine to just turn over but not fire.
I put direct power to the electric fuel pump on the side of the motor near the motor mount and the boat will fire right up and run great. So somewhere in between the pump isn't getting power.
My guess is either the fuel pump relay, a fuse, or possibly the low oil pressure cut off switch. I didn't see any fuses, but I didn't really look all that hard. I did see 2 relays on the top of the motor, 1 of which when you turn the key on makes a single "click". Im guessing this relay is the fuel pump relay as it should normally come on for a few seconds when you turn the key. The relay is nothing the auto parts stores have so im not sure where to get one.
My question is, how to I diagnose the problem from here without throwing too many parts at it? Is there a way to rule out the low oil pressure cut off switch, if it even has one? Any guesses on anything else is could be?
I put direct power to the electric fuel pump on the side of the motor near the motor mount and the boat will fire right up and run great. So somewhere in between the pump isn't getting power.
My guess is either the fuel pump relay, a fuse, or possibly the low oil pressure cut off switch. I didn't see any fuses, but I didn't really look all that hard. I did see 2 relays on the top of the motor, 1 of which when you turn the key on makes a single "click". Im guessing this relay is the fuel pump relay as it should normally come on for a few seconds when you turn the key. The relay is nothing the auto parts stores have so im not sure where to get one.
My question is, how to I diagnose the problem from here without throwing too many parts at it? Is there a way to rule out the low oil pressure cut off switch, if it even has one? Any guesses on anything else is could be?
04-23-2013, 08:23 AM
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Those relays can go bad and you should be able to get them from most marine places. You can try to swap the 2 relays to see if that is the problem, but close to them there is a relay pack with 3-4 fuses, or single enclosed fuse packs (not sure when they changed them). I would check those out and if they look good, I would get out a mutimeter to check for power to the fuses and the relay. Verify that the big red botton breaker is not tripped. It should be an easy fix once you find the problem spot, and I don't know of a low oil switch on that year/model.
04-25-2013, 04:54 AM
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[couple years back I chased this same thing for about 3 days. Even took to a marine dealer only to tell me they thought I wouldn't need a new wiring harness??? I said B/S.. Traced all wires to the pump and relays, mercruiser even changes wire colors in mid path on one wire. End result. Far right corner in the dash was a white wire loom plug. About 5-8 wires? Pulled a part saw a little corrosion, cleaned lubed put back together and fired right up... Who knew right??????
QUOTE=hillcrestnh;3910225]I have a 1999 Powerquest 22ft with a mercruiser 454 MPI with a Braveo 1 drive. The Fuel Pump is not getting power, causing the engine to just turn over but not fire.
I put direct power to the electric fuel pump on the side of the motor near the motor mount and the boat will fire right up and run great. So somewhere in between the pump isn't getting power.
My guess is either the fuel pump relay, a fuse, or possibly the low oil pressure cut off switch. I didn't see any fuses, but I didn't really look all that hard. I did see 2 relays on the top of the motor, 1 of which when you turn the key on makes a single "click". Im guessing this relay is the fuel pump relay as it should normally come on for a few seconds when you turn the key. The relay is nothing the auto parts stores have so im not sure where to get one.
My question is, how to I diagnose the problem from here without throwing too many parts at it? Is there a way to rule out the low oil pressure cut off switch, if it even has one? Any guesses on anything else is could be?[/QUOTE]
QUOTE=hillcrestnh;3910225]I have a 1999 Powerquest 22ft with a mercruiser 454 MPI with a Braveo 1 drive. The Fuel Pump is not getting power, causing the engine to just turn over but not fire.
I put direct power to the electric fuel pump on the side of the motor near the motor mount and the boat will fire right up and run great. So somewhere in between the pump isn't getting power.
My guess is either the fuel pump relay, a fuse, or possibly the low oil pressure cut off switch. I didn't see any fuses, but I didn't really look all that hard. I did see 2 relays on the top of the motor, 1 of which when you turn the key on makes a single "click". Im guessing this relay is the fuel pump relay as it should normally come on for a few seconds when you turn the key. The relay is nothing the auto parts stores have so im not sure where to get one.
My question is, how to I diagnose the problem from here without throwing too many parts at it? Is there a way to rule out the low oil pressure cut off switch, if it even has one? Any guesses on anything else is could be?[/QUOTE]
