For those of you experiencing the low fuel pressure woes caused by failed fuel pumps from EPA mandated ethanol gasolines, here's the how-to on pump and regulator replacement for most EFI Mercruiser engines through serial 0M398371. Mods should sticky this one please.
After determining your fuel pressure is not or cannot hold the required 32psi +- 2psi, locate your cool fuel module on the engine forward motor mount, engine port side. Its a neat black box, rectangular in shape. Grab the plastic tab on the middle bottom of the box and remove the cover, exposing the pump and hose connections. Disconnect the battery negatives AT THE BATTERIES and wrap them prior to starting this job. Inadvertent sparks while performing this repair will end poorly for all involved.
I cannot recommend enough to purchase OEM. Cheap pumps will initially work and then leave you stranded. Buy OEM parts for this job or you will throw good money after bad.
Plan on purchasing the brass fuel fitting connection at the fuel pressure regulator, Mercruiser P/N (#22-808002A1), for an additional $30. It will be a lifesaver if the old one breaks during removal, which they usually do.
1) Disconnect water inlet and outlet water hoses (you will most likely need a hose removal tool, those bastards are welded in place)
2) Disconnect the fuel line inlet to the fuel/water separator and plug with a 3/8" bolt, tying the hose as high in the bilge as possible to keep fuel from siphoning
3) Plug or cap (whatever is required) the fuel inlet to the filter. The filter and housing will be unbolted and dragged through the bilge and if its not plugged or capped, gas will end up in the bilge.
3) Unbolt the filter housing from the mount and replace the nuts back on their studs once the filter housing is removed. LEAVE THE OTHER 2 FUEL LINES ATTACHED!!!
4) Disconnect the vacuum hose from the fuel pump regulator on top of the fuel pump
5) At the top of the engine port side fuel rail next to the distributor, disconnect the high pressure fuel line being aware of the hard line tubing, brass inverted flare fuel nut and making sure to use the correct size open end wrench so as not to compromise their ability to seal when re-installed. Gasoline spraying from this area is bad. Have multiple rags ready to catch the fuel draining from the fuel rail when the nut is loosened.
6) Disconnect the electrical connection at the fuel pump.
7) Unbolt the pump from the motor mount. It is held in place with 2 nuts, 9/16" hex heads.
8) Drag the whole apparatus, fuel lines and fuel filter out of the boat.
9) Remove the pump and cooler assembly from the housing making sure to not get any white heat dissipating grease on your skin, it burns like bad things.
10) If you did not buy a new brass fitting that goes into the fuel pressure regulator you will have to remove the existing unit and hope it does not break. Disconnect its corresponding fuel hose and then disconnect the fitting, keeping the copper crush washer with it to reuse too.
11) Assemble the new pump using o-rings and grease supplied in the cooler kit. This is also where OEM gives you the correct stuff.
12) Install the new fuel pressure regulator making sure the tiny screen is installed in the copper tube prior to bolting down the regulator. If you have questions on orientation, look at the old one because you'll need the screws from the old pressure regulator.
13) Install the brass fitting in the pressure regulator.
14) Install the pump and fuel cooler making sure to use grease on the water drain plastic plug and o-ring. Use the supplied heat dissipating white grease on the pump too just don't touch it without gloves.
15) Install back on the engine, reverse of removal.
16) Bleed the fuel rails by allowing the fuel pump to pressurize and bleed the air out at the fuel pressure test port (lots of rags required to catch gas).
17) Look, listen and smell for gas leaks. It's very important to not have any leaks after completing the job.
After determining your fuel pressure is not or cannot hold the required 32psi +- 2psi, locate your cool fuel module on the engine forward motor mount, engine port side. Its a neat black box, rectangular in shape. Grab the plastic tab on the middle bottom of the box and remove the cover, exposing the pump and hose connections. Disconnect the battery negatives AT THE BATTERIES and wrap them prior to starting this job. Inadvertent sparks while performing this repair will end poorly for all involved.
I cannot recommend enough to purchase OEM. Cheap pumps will initially work and then leave you stranded. Buy OEM parts for this job or you will throw good money after bad.
Plan on purchasing the brass fuel fitting connection at the fuel pressure regulator, Mercruiser P/N (#22-808002A1), for an additional $30. It will be a lifesaver if the old one breaks during removal, which they usually do.
1) Disconnect water inlet and outlet water hoses (you will most likely need a hose removal tool, those bastards are welded in place)
2) Disconnect the fuel line inlet to the fuel/water separator and plug with a 3/8" bolt, tying the hose as high in the bilge as possible to keep fuel from siphoning
3) Plug or cap (whatever is required) the fuel inlet to the filter. The filter and housing will be unbolted and dragged through the bilge and if its not plugged or capped, gas will end up in the bilge.
3) Unbolt the filter housing from the mount and replace the nuts back on their studs once the filter housing is removed. LEAVE THE OTHER 2 FUEL LINES ATTACHED!!!
4) Disconnect the vacuum hose from the fuel pump regulator on top of the fuel pump
5) At the top of the engine port side fuel rail next to the distributor, disconnect the high pressure fuel line being aware of the hard line tubing, brass inverted flare fuel nut and making sure to use the correct size open end wrench so as not to compromise their ability to seal when re-installed. Gasoline spraying from this area is bad. Have multiple rags ready to catch the fuel draining from the fuel rail when the nut is loosened.
6) Disconnect the electrical connection at the fuel pump.
7) Unbolt the pump from the motor mount. It is held in place with 2 nuts, 9/16" hex heads.
8) Drag the whole apparatus, fuel lines and fuel filter out of the boat.
9) Remove the pump and cooler assembly from the housing making sure to not get any white heat dissipating grease on your skin, it burns like bad things.
10) If you did not buy a new brass fitting that goes into the fuel pressure regulator you will have to remove the existing unit and hope it does not break. Disconnect its corresponding fuel hose and then disconnect the fitting, keeping the copper crush washer with it to reuse too.
11) Assemble the new pump using o-rings and grease supplied in the cooler kit. This is also where OEM gives you the correct stuff.
12) Install the new fuel pressure regulator making sure the tiny screen is installed in the copper tube prior to bolting down the regulator. If you have questions on orientation, look at the old one because you'll need the screws from the old pressure regulator.
13) Install the brass fitting in the pressure regulator.
14) Install the pump and fuel cooler making sure to use grease on the water drain plastic plug and o-ring. Use the supplied heat dissipating white grease on the pump too just don't touch it without gloves.
15) Install back on the engine, reverse of removal.
16) Bleed the fuel rails by allowing the fuel pump to pressurize and bleed the air out at the fuel pressure test port (lots of rags required to catch gas).
17) Look, listen and smell for gas leaks. It's very important to not have any leaks after completing the job.
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