Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   502 efi fuel pump replacement (https://www.offshoreonly.com/forums/general-q/385472-502-efi-fuel-pump-replacement.html)

tristan247 05-27-2025 12:34 PM

502 efi fuel pump replacement
 
Currently re building a pair of Gen 6 502 efi. they actually started their life as a Volvo 8.2 unit. since then many rebuids and bottom end components changed before I have got them. So they still run the standard low pressure fuel pump with cooler fitted to the rear of the engine, I want to junk this unit and replace. they have ANSU matched injectors, MSD ignition with marine 6M-2L boxes. Holley high pressure fuel pumps. What can I do to remove and replace the old low pressure fuel cooler unit ?
Thanks

F-2 Speedy 05-27-2025 12:46 PM

post a pic of what you are wanting to remove, Im a little confused

tristan247 05-29-2025 02:20 PM


Originally Posted by F-2 Speedy (Post 4926972)
post a pic of what you are wanting to remove, Im a little confused

How can I get pics on, I will take some of the unit fitted to the engine. So I have a holley fuel pump bulkhead mounted then in the attached parts view bellow I have unit 20-21 on the rear of the engine. Which I want to replace?

Part Sections: Fuel system and lower intake manifold - Volvo Penta Shop

DrFeelgood 05-29-2025 02:36 PM

That diagram seems to indicate that #20 is the high pressure pump, not low.

tristan247 05-29-2025 02:39 PM

Sorry yes. High pressure with fuel cooler.
seen rear of engine here

https://cimg1.ibsrv.net/gimg/www.off...327f981935.png

tristan247 05-29-2025 02:43 PM

the water fed ends and inside is getting corroded, pumps are years old. from stripping one engine I just caught a piston going bad with lean signs on the edge of it.

F-2 Speedy 05-29-2025 04:04 PM

Volvo seems a bit different than Mercury, but most remove the pump and regulator and replace with after market like Aeromotive so such and run a return line to either the water filter head or filler neck of the fuel tank, you can hook the wather hose together with some kind of coupler pipe

tristan247 05-29-2025 04:17 PM

Thanks. Is it just as easy as find out what pressure the standard pump runs at. And find an after market of the same ?
The Holley infront of this must just feed that pump from fuel tank. Low pressure

F-2 Speedy 05-29-2025 04:25 PM

that correct the Holley is a lift pump that feeds the high pressure pump that feeds the EFI rail, yes Id get a replacement pump and be done with it

tristan247 06-02-2025 01:04 PM


Originally Posted by F-2 Speedy (Post 4927162)
that correct the Holley is a lift pump that feeds the high pressure pump that feeds the EFI rail, yes Id get a replacement pump and be done with it

Do you know what psi or litre per hour is needed for these ?


All times are GMT -5. The time now is 09:08 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.