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MERCRUISER 50L EFI FUEL PUMP

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stepnewm

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"I dont think my fuel pump is

"I dont think my fuel pump is working, it is a elecrical one on my sea ray sundacer 240 1999. 5.0l EFI. It was working perfect but the bilge pump stop working and i think the water level reached the pump, And it cut out one day and now it dont start, I have taken the fuel pipe off the carb, tried to turn it over but no fuel pumping out, i have put a new fuel filter in. can ajust ny one adive me on this and what do i need to replace..many thanks"
 
"Steve, have you checked the f

"Steve, have you checked the fuel pump relay is clicking when you turn your ignition on, also check the small blade fuses in the holder ( theres 4 of them ), also check the conections to the pump plug, this is what an MPI has, not sure if it's the same as the carb set up but if it is it may help"
 
"Hi, When i turn the ignition

"Hi, When i turn the ignition on, there is a noise comming from the engine bay, for about 3 secounds then stops, I have taken off the fuel pipe at the carb, sucked it a few times and now and again, when i yurn engine over some fuel does pump out, but then stops.many thanks.
It has a carb, 5.0l EFI Engine."
 
"Hi all, NO,,, The carb is not

"Hi all, NO,,, The carb is not filling up, as i have said, no fuel comming up the pipe to the carb, and filling the carb, thats the problem. But i have talked to a Mercruiser mechanic in Plymouth today, and he said, I might have a problem with my oil pressure valve, which stops fuel comming through if i dont have any oil pressure, makes sense to cut off the engine, he said look for a corosive wire first, if not he will plug it into his lap top. Any one else out there got any ideas. cheers."
 
steve newman
You state in you

steve newman
You state in your OP you have EFI is that not Electronic Fuel Injection? I'm confused here.
Bert
 
"Hi Bert, on my engine it says

"Hi Bert, on my engine it says 5-0l efi, i am guessing it is electronic fuel injection to the carb, guest a guess."
 
"Steve, are you sure it is a c

"Steve, are you sure it is a carb and not the the throttle body your reffering to, if it is EFI, then surely it has injectors.....sorry if i am missing something here"
 
steve newman
If it was inject

steve newman
If it was injected at the throttle body(carb) it should be listed as TBI Throttle Body Injection. Got a picture??
Bert
 
Check the 12 vdc wiring from t

Check the 12 vdc wiring from the fuel pump to a junction w/a connector; corrodes at that point. FP relay still could be the problem. It may be clicking but motor contacts burned.
 
"cheers guy i will do this the

"cheers guy i will do this the weekend, ok lets get this right once and for all. my engine has spark plugs and a carb. a fuel pipe goes up to the carb, but no fuel comming from the pipe. i will check what guy says this weekend,."
 
"Assuming you do have a actual

"Assuming you do have a actual carb, look just above the oil filter on the engine.sender has 1 wire, pressure switch had 2"
 
"could you please tell me wher

"could you please tell me where the fuel pump presure swith is?? i dont have a carb, its a throttle body, which i thought was a carb, are we saying the fuel pump pressure switch is the regulator??? cheers"
 
"I have it all in bits now, as

"I have it all in bits now, as i got off the electronic fuel pump,
I think whats not working is this pump, as I disconected it, conected direct to a battery, still had the fuel conected to it, and put some power through it, and it made a noise but did not pump any fuel through it, does this mean the fuel pump in knackerd,, i am thinking yes, and will get it checked out on monday, any ideas people please."
 
"steve newman
Could mean a co

"steve newman
Could mean a couple of things. The fuel pump is shot, the inlet fuel line is plugged, the fuel tank is empty.
Bert"
 
"Bert, Thank you, this is what

"Bert, Thank you, this is what i wanted to hear, because I have checked the fuel tank and its half full. I sucked on the inlet fuel line and got a nice mouth full of fuel,yuk. so i think you have confirmed that the fuel pump is shot.
thank you"
 
"Steve, sounds like you are on

"Steve, sounds like you are on the right track, as far as assuming faulty fuel-pump. Most marine parts dealers, or in my area, NAPA would be able to test electrically or pressure test to confirm.

If this tests as good, on the port side of your engine is an Oil Pressure switch, which also supplies 12-v to the fuel pump. If you loose O/P, this will shut off the supply to the fuel pump as a safety.

On my 2000 5.0 Mercruiser, I found the connector about 6-inches from the O/P sensor had a bunch of crud/oil/dirt causing poor connection, and random engine dying due to starvation of fuel. Sprayed with degreaser, then lightly with acetone, coated with electrical grease and been fine ever since.

Good-luck!"
 
"Also, I believe this fuel pum

"Also, I believe this fuel pump has an inlet filter inside the large brass nut. Remove this to inspect."
 
"With TBI and MPI, the ECU &#4

"With TBI and MPI, the ECU (MEFI 1-3) controls the fuel pump thru the fuel pump relay. At "Key On" the pump will only run for 2 seconds to pressure up the fuel system. Key in the "crank" position, the fuel pump runs again. Key On with engine running above 300 RPM, fuel pump continues to run.

With the carb. models with electric fuel pump, Joe is correct in saying the fuel pump is controlled thru the oil pressure switch as the safety feature."
 
"Hi all, WELL i have sorted it

"Hi all, WELL i have sorted it out, after talking to you all, i spoke to my mercruiser engineer, and told him my pump sounds like its working but no fuel comming out, but if i suck it, loads of fuel pums out. my dealer said this is wrong, it should be self bleeding pump, so he told me the fuel pump was no good, so i bought a new pump,Ouch that hurt, fitted it on, and hey presto, it works perfect and engine fired up and runs a dream again. so thank you all for your advice, all now sorted. cheers. steve"
 
"Having the same issues here a

"Having the same issues here also.

I was instructed to change my water fuel seperator, which I have done and it hasn't helped in anyway.

Thanks for the info here I will try your suggestions."
 
"Dana, my fuel pump is located

"Dana, my fuel pump is located, looking at the engine and pullys to the front, its on the right hand side, under the engine next to the engine mount in a square black plastic box, go to this web site and put your details in and it will show you what your pump looks like.www.crowleymarine.com. good luck"
 
"Some great ideas here.I have

"Some great ideas here.I have just reinstalled my 5.7L MAG MPI after a rebuild.The fuel pump is not priming when ignition switch on. Found some dodgy connections on the pigtail to engine harness and bypassed this but no good. Fuses are ok. Joe's info on the oil pressure sounds good. I will be back with the results, many thanks"
 
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