no power to fuel pump after starting

Joined
Aug 12, 2007
Messages
10
I have a 94 rinker 190 captiva with merc 4.3 ltr, we were out and the boat started lunging I slowed and it started going again, then it happend again, finally it got to the point where you could start it and it would go 15 freet and die, so here is my diagnosis, after many tests were done I replaced the fuel filter and ouch the $500.00 fuel pump, to find it does the same thing, when you turn the key you get power to the fuel pump, this allows enough gas to fill the carb, then engine will run untill carb emptys and die, then you can do the same, I checked the wire from the starter and no power there either, I can run power direct to the pump and it works fine, I put test light on fuel pump wire and found the light comes on when you start the engine, soon as engine starts light goes off, thus no power to fuel pump, I assume there must be some safety switch not working, or could this be the secondary power from either the starter solenoid or the ignition, I thought the secondary on the solenoid must be ok or the engine wouldent stay running when you let off the key???? I cant afford to throw parts at it & now that I have a 500.00 non returnable fuel pump, help pleasssse Thanks:(
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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62,321
Re: no power to fuel pump after starting

What do you have? Merc, Volvo, OMC
 

Haut Medoc

Supreme Mariner
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Jun 29, 2004
Messages
10,645
Re: no power to fuel pump after starting

It sounds like the oil pressure switch has gone bad......
It shuts off the fuel pump if insufficient pressure is present.....
I'm sure Don will post up his pic of your scenario & how to fix it, so stick around.......;)
Welcome to iboats, btw......:)
 
Joined
Aug 12, 2007
Messages
10
Re: no power to fuel pump after starting

It sounds like the oil pressure switch has gone bad......
It shuts off the fuel pump if insufficient pressure is present.....
I'm sure Don will post up his pic of your scenario & how to fix it, so stick around.......;)
Welcome to iboats, btw......:)

thanks I am watching
 

Don S

Honorary Moderator Emeritus
Joined
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Messages
62,321
Re: no power to fuel pump after starting

The oil pressure switch is located above the oil filter boss on the port/aft part of the block and has 2 terminals on it. Put a jumper wire across the 2 terminals of the switch and see if it will keep running after startup. If it does, replace the switch.

FuelPumpWiring.jpg


Had the wrong picture at first!!!!
 
Joined
Aug 12, 2007
Messages
10
Re: no power to fuel pump after starting

that sounds right, wish i had came here before buying the fuel pump, I will go try that, thenks, I will post results Thanks Mike
 
Joined
Aug 12, 2007
Messages
10
Re: no power to fuel pump after starting

well that was an expensive lesson, I found the wire to the oil pressure switch off, last week I changed the oil and filter, I must have knocked the wire loose,and then after running it came off , boy do I feel stupid, Thanks for the help Mike
 

180shabah

Rear Admiral
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Mar 26, 2005
Messages
4,995
Re: no power to fuel pump after starting

Glad you got it running, Mike.
 

skydyvyr

Recruit
Joined
Aug 14, 2007
Messages
4
Re: no power to fuel pump after starting

I think I'm having a similar problem. Is the oil pressure sender next to the distributor and if so, which sender is it? My boat has a brass t-fitting with two senders attached that is constantly leaking oil... is there a single sender that will switch the fuel pump and drive the oil pressure gauge?
 

Haut Medoc

Supreme Mariner
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Messages
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Re: no power to fuel pump after starting


Welcome to iboats.....:)
You should post your year, make & hp & serial # if possible.....
& start your own thread to gat a better response from the forum....;)
 

skydyvyr

Recruit
Joined
Aug 14, 2007
Messages
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Re: no power to fuel pump after starting

Sorry, I should have included that I have the same powerplant ('94 Merc 4.3 l).
 

Don S

Honorary Moderator Emeritus
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Messages
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Re: no power to fuel pump after starting

As Haut mentioned before, start a new thread. Don't just tack on to someone elses thread with your question, not only will your question get lost in the replies, but no one will really see yours and keep replying to the original post.
 

skydyvyr

Recruit
Joined
Aug 14, 2007
Messages
4
Please forgive my ignorance

Please forgive my ignorance

I didn't start a new thread as it seemed that my question was an extension of one that already existed and did not want to clutter the board root with questions that seemed to be repetitive, so I just tried to follow up on an existing active thread.

I know that I am new to this board, however I'm not new to boards in general and was trying to follow etiquette that I'm familiar with from elsewhere.

Please forgive me if this seems argumentitive or flame like as that is not my intention at all.
 
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