2002 Mercruiser 4.3L MPI Fuel Pump Style

[Chris M Wilson]

Has anyone changed the electric fuel pump on a 2002 4.3L Mercruiser with MPI? The pump has a cooler manifold for the fuel. When searching for replacement on line I have noticed that there are some pumps that warn that one of the pump ends is 'not' threaded. This seems weird considering the application but also implies that there are pumps that are threaded on both ends. My question is, "Does anyone know what style is used with the cool system (the manifold is tubular in shape) for this engine?". I have removed the outer casing but getting a good view of the connection points for the pump is very difficult and I can't tell from the vantage point I have. I know there are different pressure ratings and expect the pump that goes to this engine is of the higher pressure style since it is for a MPI system and not a regular carburated system. For what its worth, the existing pump is labeled SAE J1171. I think this is more of some sort of classification from the Society of Automotive Engineers and does not give me confidence I am looking at the right electric fuel pump when I search on that information.

Hope someone can help. Any assistance with model numbers that might apply would also be greatly appreciated.

 

[alldodge]

Merc doesn't make it anymore but others do. Just look up the part number using your motor serial number then search for that number

 

[Scott06]

just a note to OP - SAE J1171 will be on all electrical components ( maybe fuel components too) that are marine rated. Vs automotive the alternators fuel pumps distributors etc will have design features to prevent spark and fuel vapor explosions and fire . it not the part number for the component

 

[achris]

Has anyone changed the electric fuel pump on a 2002 4.3L Mercruiser with MPI? The pump has a cooler manifold for the fuel. When searching for replacement on line I have noticed that there are some pumps that warn that one of the pump ends is 'not' threaded. This seems weird considering the application but also implies that there are pumps that are threaded on both ends. My question is, "Does anyone know what style is used with the cool system (the manifold is tubular in shape) for this engine?". I have removed the outer casing but getting a good view of the connection points for the pump is very difficult and I can't tell from the vantage point I have. I know there are different pressure ratings and expect the pump that goes to this engine is of the higher pressure style since it is for a MPI system and not a regular carburated system. For what its worth, the existing pump is labeled SAE J1171. I think this is more of some sort of classification from the Society of Automotive Engineers and does not give me confidence I am looking at the right electric fuel pump when I search on that information.

Hope someone can help. Any assistance with model numbers that might apply would also be greatly appreciated.

Post your engine serial number and I can look up the pump for you. Just curious, why are you looking at changing the pump?

Chris....

 

[Chris M Wilson]

Post your engine serial number and I can look up the pump for you. Just curious, why are you looking at changing the pump?

Chris....

Hi. Thanks for the response. The pump is getting pretty noisey and has intermittent issues with starting. I have some info on the boat but already removed the pump to get a closer look. In addition to the J 1171 tag there are numbers stamped on the casing. Hopefully this will come through with the spacing. The info is shown on two lines:
861156-1
1002 A
I am not near the boat now but the info I have from the mfg plate is:
0M355000
I am not sure if that is the engine serial number you are referencing. I have been searching against that number and come across a variety of 'supposedly' equivalent aftermarket pumps. The Mercruiser part number from the mercruiser part site is: 861156A1. I realize that they now only sell the pump as part of a kit that includes the cooler. However there appear to be a lot of pumps that come up without the cooler in a wide range of prices. My concern is that not all the aftermarket pumps shown 'really' have the pressure and flow to be a true replacement. I believe the operating pressure for this 2002 4.3 L MPI is arounnd 42 psi, but I don't know what the pump capacities should be to keep that pressure. Surely it is some amount higher and has some minimum flow spec.

I am not sure paying $50 or $300 is going to match the design and hopng to learn a little more so I can at least ask some these aftermarket suppliers what the pump specs are. Hope you can help.

 

[alldodge]

The 0M number is the serial number, and your correct 861156A1 is the pump part number. Just search on it and it will show several that will work

The pump can pressurize more then 42psi but the regulator (item 13) which is attached to the cooler keeps the pressure constant. The noise might be a worn pump but could also be that there is a restriction (fuel line, antisiphone valve) which is causing the pump to have a harder time getting fuel to it. Measure the pressure

https://www.mercruiserparts.com/bam/subassembly/31499/7801/50

 

[achris]

Hi. Thanks for the response. The pump is getting pretty noisey and has intermittent issues with starting. I have some info on the boat but already removed the pump to get a closer look. In addition to the J 1171

SAE J1171 is the standard required for marine electrical equipment. You'll find that same number on alternators, starter motors, relays, switches, pump motors, etc. That just means it meets the standards requirement.

tag there are numbers stamped on the casing. Hopefully this will come through with the spacing. The info is shown on two lines:
861156-1

That's the part number.

1002 A
I am not near the boat now but the info I have from the mfg plate is:
0M355000

That's your engine serial number, and the one we need to find out the specific parts in your engine.

I am not sure if that is the engine serial number you are referencing. I have been searching against that number and come across a variety of 'supposedly' equivalent aftermarket pumps. The Mercruiser part number from the mercruiser part site is: 861156A1. I realize that they now only sell the pump as part of a kit that includes the cooler.

That's right, the original pump is NLA (No Longer Available) and has been superseded by a kit which includes a cooler, and is a DIRECT replacement for the pump you have.

However there appear to be a lot of pumps that come up without the cooler in a wide range of prices. My concern is that not all the aftermarket pumps shown 'really' have the pressure and flow to be a true replacement. I believe the operating pressure for this 2002 4.3 L MPI is arounnd 42 psi,

That's the right pressure for these engines, and the pressure regulator is what controls that pressure. The pumps is capable of producing over 50psi...

but I don't know what the pump capacities should be to keep that pressure. Surely it is some amount higher and has some minimum flow spec.

I am not sure paying $50 or $300 is going to match the design and hopng to learn a little more so I can at least ask some these aftermarket suppliers what the pump specs are. Hope you can help.

Without detailed knowledge and information, I wouldn't trust an aftermarket pump in this situation. I'd bite the bullet on the Merc gouge. The correct replacement for your pump is Merc part number 8M0125852.

Chris........

 

[QBhoy]

What is noisy about it ? Presumably it’s not making a noise that might indicate losing its prime or drawing air ?