2002 Mercruiser 4.3 no power to fuel pump

tomkimbrel

Recruit
Joined
Jun 17, 2013
Messages
5
I have a 2002 Bayliner Capri Runabout with a Mercruiser 4.3. My boat has very low hours about 200. Last year July 2012, the motor quit and was not getting fuel to the carb. I replaced the fuel filter at that time (it was clean with no water). The boat started and ran for a short time. After that it quit and had to be towed to my trailer. I got it home and replaced the fuel pump. I hooked up fresh water to it and it started and ran fine in my front yard on the trailer. I put it away for the winter and this spring May 2013, it would not start. I jumpered the fuel pump and the pump ran fine. The boat started until the fuel ran out of the float bowl on the carb. After that it would not start. It appears that I have no power at all, not even when the ignition switch is turned to start. The motor cranks over just fine and I have checked all the fuses under the cowl and I have checked the wiring connections at the starter solenoid, the oil pressure switch and all the purple and yellow-purple connections I could find. I am at a loss on what to check next. Can anyone help?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 2002 Mercruiser 4.3 no power to fuel pump

Sounds like you have either a faulty oil pressure switch or corroded wires going to it.

Fuel Pump Wiring.jpg
 

tomkimbrel

Recruit
Joined
Jun 17, 2013
Messages
5
Re: 2002 Mercruiser 4.3 no power to fuel pump

Good wiring diagram!!! Thanks, is there a fuel pump relay I don't know about? Maybe something not shown on the diagram?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 2002 Mercruiser 4.3 no power to fuel pump

Nope, no relays on carbed engines, the system is as shown in the diagram.
 

tomkimbrel

Recruit
Joined
Jun 17, 2013
Messages
5
Re: 2002 Mercruiser 4.3 no power to fuel pump

Thanks, I will do some thorough checking and get back to you.
 

tomkimbrel

Recruit
Joined
Jun 17, 2013
Messages
5
Re: 2002 Mercruiser 4.3 no power to fuel pump

Jumpered the fuel pump at the pressure switch and it would not run with the ign switch in the run position. Could the ignition module prevent power from going to the fuel pump?
 

tomkimbrel

Recruit
Joined
Jun 17, 2013
Messages
5
Re: 2002 Mercruiser 4.3 no power to fuel pump

Finally found and fixed the problem, was a faulty connector from fuel pump to motor electrical
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,525
Re: 2002 Mercruiser 4.3 no power to fuel pump

Finally found and fixed the problem, was a faulty connector from fuel pump to motor electrical

Ayuh,.... Welcome Aboard,... Glad ya found it,...

That Is a pretty funky connector to a connector, to the motor,...
 
Top