Fuel Pump

xcelr8z28

Seaman Apprentice
Joined
May 22, 2007
Messages
49
How can I tell if my fuel pump is mechanical or electric??
Engine is Mercruiser 4.3LX # OD833432
1993 ebbtide bowrider

I've tried to listen to it turn on in ACC like you would in a car but I cannot hear anything buzzing in the gas tank. Maybe is located else where. Please point me in the right way.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,088
Re: Fuel Pump

Ayuh,.....

The fuel pump is mounted on the forward starboardside of the motor.....

A Mechanical pump will be bolted to the Block.....
An Electric pump will be in the same general area,+ have Wires going to it.....

Boat fuelpumps do Not run with the key on the "Acc." position....
'Course,... It don't run in the "On" position Either,....
Unless the motor has Oil Pressure......
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Fuel Pump

Follow the fuel line from the carb to the fuel pump. If the pump has wires on it, it's electric.
On that SN, it should be electic, but it doesn't work like cars with EFI. On a carbed engine, the pump only comes on when you crank the engine. Once it starts, and oil pressure switch closes to keep it running.

BTW, What is your problem exactly.
 

xcelr8z28

Seaman Apprentice
Joined
May 22, 2007
Messages
49
Re: Fuel Pump

I am installing a fuel water seperator system as is recommended from the guys at the local marina, but in the directions it says not to use the kit if the boat is equiped with an electric fuel pump. For some reason in 1992 they didn't put the fuel water seperator on the 4.3LX just has a filter in the line.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,088
Re: Fuel Pump

but in the directions it says not to use the kit if the boat is equiped with an electric fuel pump.

Ayuh,..... I wonder Why,..??..??
 

xcelr8z28

Seaman Apprentice
Joined
May 22, 2007
Messages
49
Re: Fuel Pump

Yup i got that and that the kit I baught, just didn't get an answer about the fuel pumps until now.. Didn't want to go start cutting up the fuel lines without knowing what kind of pump I had, It says in the directions that installing the water seperator kit with an electric pump will cause poor pumping of gas into the carberator, not sure why it would make a difference but its written in the directions. Anyways im headed in the right direction now thanks a bunch!!!
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Fuel Pump

What is really odd, is that is the kit that Mercruiser says to use in place of the inline filter that is NLA, then in their own instructions say it can't be used on an electric fuel pump. Makes ya really wonder if the left hand knows what the right hand is doing at Merc.
Basically, the kit was designed for an 8.1, that uses a LOT more fuel in GPH than your 4.3 does. Install the kit and you will be fine.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,088
Re: Fuel Pump

Makes ya really wonder if the left hand knows what the right hand is doing at Merc.

Ayuh,.... I Donno,.....

But I Do know that Merc just Don't Care where You've got to put Both of Your Hands,.......;)
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Fuel Pump

Mercruiser sees engine on test stands, visit a school some time. Has absolutely nothing to do with working on them while in a boat. And the boat manufactures think motors and parts never break, A perfect Lose-Lose relationship for owners and mechanics.
 
Top