Reply With QuoteCheck the fuel line clamps. Might be sucking air.
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Minnow
Mercury fuel pump issue?
Today on the way back to the ramp my ‘13 90hp 4stroke lost power and would barely run. Had to get towed in. It sounded like it was running out of gas. So I removed the cowing and checked the pressure check valve to see if I had any pressure. When I pushed in on the valve a lot of air and gas spewed out and eventually nothing came out while the key was on. Any ideas? It like it was trying to pressure up but can’t get enough fuel. Thanks in advance
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Check the fuel line clamps. Might be sucking air.
MEMBER CRAPPIE MAFIA
Minnow
I checked the ones on the filters. Anywhere else? I used to sometimes hear the pump running when I turned the key on and I don’t anymore.
Crappie.com 2019 Man of Year, Supermod & Moderator of the Mechanics Forum
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Sounds like your electric transferes pump has gone out. Mounted on front of motor in a plastic box/reservoir it also contains a filter in there.
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Charlie Weaver USN/ENC 1965-1979
Minnow
So I just took the plastic housing off and the container apart. Is the transfer pump the one with the filter? And how would I know it’s bad? Thanks for the help btw
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When you turn the key on it should start running until it builds up so much pressure then it should cut off. Then if you start it up and start burning gas it should kick on and off to keep fuel pressure up.. Should be a port like a a/c port some where close that is for hooking up fuel pressure gauge. Should be able to depres valve inside to see if you have fuel coming from the pump.Originally Posted by istuffanimals
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Charlie Weaver USN/ENC 1965-1979
Minnow
I’ve checked both pumps and they tested good. The gas that comes out of the port/pressure check valve is sometimes foamy or fizzy and sometimes good and clear. I’ve read something about a fuel supply module being an issue. Ever heard of that? Looks like it’s possibly beyond my capabilities. But thanks for the advice. Very appreciated
Crappie.com 2019 Man of Year, Supermod & Moderator of the Mechanics Forum
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I have heard about that module but know nothing about it. Working with a friend that’s having issues very similar to yours. One more simple thing to check, if you haven’t done this, check all the connections from tank o pump for any leaks. His does the same fizzing like it’s getting some air in system. I would think that is not normal if it has a good fuel supply and pump is up to snuff. Other than that it may be time to bite the bullet.
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Charlie Weaver USN/ENC 1965-1979
Minnow
It’s like it’s not telling the fuel lift pump to get enough fuel to the fuel pump itself. Keep me posted on your friends and I’ll let you know what the mechanic says. Thanks again greatly appreciated
Crappie Wall Hanger II
Unless you're working on something I've never seen, the lift pump is a mechanical pump that operates off the cam. The electric pump is the high pressure pump that feeds the injectors. Foam like samples coming from the service valve is not too uncommon. It may be a sign of the system drawing air IF the motor is running at the time. If it's a static test, it is probably lowering the fuel level in the VST to the point that it's drawing some air as the level drops.
Your original problem may be fuel related, but your description could also describe limp mode operation.
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