Electric fuel pump problems

[Mike517]

I am new to this forum and fairly new to boating I have a 1995 Sea Swirl Model 201 with the 5.0L Cobre V8 engine. I have replaced the
electric fuel pump 2 times in 2 outings. The pump fails after about a day of boating. Using an ohm meter at the connector the pump
shows an open circuit. All wiring seems to be in good shape. I have no schematics so I do not know if it is wired properly. What is the
electrical flow for the fuel pump, does it run from Key switch, a relay, starter selenoid, alternator ect
Any help would be appreciated Thanks
Mike

 

[Bondo]

with the 5.0L Cobre V8 engine.

Ayuh,..... Welcome Aboard,..... Do ya have the full alphanumeric model number of yer motor/ drive,..??

There were several 5.0l options,.....

 

[Mike517]

Ayuh,..... Welcome Aboard,..... Do ya have the full alphanumeric model number of yer motor/ drive,..??

There were several 5.0l options,.....

I have the outdrive numbers but will try to get the motor number probably tomorrow.
Thanks

 

[Mike517]

Ayuh,..... Welcome Aboard,..... Do ya have the full alphanumeric model number of yer motor/ drive,..??

There were several 5.0l options,.....

The engine is 5.0L OMC Cobre by Volvo Penta 50FACPMDA T01266106 the drive is 3866076 sn10788324 ratio 1.66 this motor has 2 fuel pumps and is EFI
the pump that is failing is the primary connected to the fuel tank. Both pumps operate for a few seconds untill pressurized when key is turned on. The secondary pump ,pumps from a reservoir that has schrader valve and feeds fuel rail. I will change filter and make sure line is clear to the tank. What should the pressure be at the schrader valve. The failed pump is not marked for brand but has these numbers 3858261, 60713 and 218-1433A . it also appears both the primary and secondary pumps are same.I will also change the relay. It also appears both pumps share same relay. After a failure once the pump is replaced it starts right up
Any info or suggestions would be helpful, Thanks
Mike517

 

[bruceb58]

More used to the GM engines in which the 2 pumps are different. The low pressure pump draws fuel from the fuel tank and is pretty low pressure...6PSI. The next pump is high pressure and should be higher pressure which is over 25PSI.

I wonder if someone replaced the low pressure pump with a high pressure pump accidentally at some point.

EDIT: Confirmed that 3858261 is a low pressure pump.

 

[Mike517]

More used to the GM engines in which the 2 pumps are different. The low pressure pump draws fuel from the fuel tank and is pretty low pressure...6PSI. The next pump is high pressure and should be higher pressure which is over 25PSI.

I wonder if someone replaced the low pressure pump with a high pressure pump accidentally at some point.

EDIT: Confirmed that 3858261 is a low pressure pump.

Thanks Bruceb58, I have found filter is ok and with new low pressure pump I have good pressure into the reservoir, It seems to run well, In the past it will run good for several days then just die and it always seems to be the low pressure pump has an open in the wiring to pump as shown using OHM meter. change pump and starts right up.. May be bad manufacture of pump wiring, It seems that pump will have power at all times when key is on, It pressurizes then stops pumping then runs when needed, Does anyone know if these pumps have a pressure switch or flow switch built internally, I dont think there is a problem with the reservoir as it runs well until low pressure pump fails. One thing is that is that it has happened twice right after filling the fuel tank could it cause a problem if fuel is upto or above the tank vent

 

[bruceb58]

That is the Ford fuel injection system and ECU so the pump is controlled by the ECU. I have no idea how Ford does things so can't help you.