DESPERATE 1994 merc 150 EFI won't start (normally perfect)

[robowenh]

HISTORY: I put this 94 merc 150efi motor on my 17 mako. It ran great but at high rpm's would suck the primer bulb flat. I'm thinking fuel restriction in the tank; I replaced a few filters and floats and tried to clean the vent and it worked some, but at higher rpm's would suck flat.<br /> This never affected the motor, always started and ran great. <br /><br />PROBLEM: Recently I went to start the motor and it would not start. After about 10min of priming and choking it finally ran for about 10min perfect and then stalled, and would not start back up. I am noticing a humming sound that appears to be coming from the fuel pump in the motor when the key is turned on, if left on it eventually stops, but it still doesn't start and then the pump(sounds like a fuel pump but unsure) starts humming again.<br /><br />please help desperate for answers mini season around the corner <br /><br />fuel-2wks old with stabilizer <br />spark plugs-new<br /><br />HELP

 

[WillyBWright]

Re: DESPERATE 1994 merc 150 EFI won't start (normally perfect)

The electric fuel pump will run for about 20 seconds unless the motor starts, then it'll keep running. If the motor doesn't start, then it'll stop after 20 seconds.<br /><br />I'd pull the fuel tank pickup. One boat I worked on had the pickup clogged with carpet fibers. Don't know how they could've gotten there except for someone at the boat factory messing around. One way or another I'd replace the antisyphon valve. It could be sticking. So could the primer bulb. They made real crappy ones for awhile. The newer ones have better innards, at least if you get the Mercury or Johnnyrude ones. If you have an aftermarket fuel line, CHUCK IT! They're all Pure Crapola! Not some, not most. !ALL! AFTERMARKET FUEL LINES ARE PURE CRAP!!!!!!!!!!! Haven't run across one I'd use to syphon gas for my old POS lawnmower! If the USCG got up the balls to recall every one of them and bankrupted every manufacturer of them, I wouldn't feel a bit sorry for any one of them. PURE CRAP! (I hope I'm not being ambiguous. )

 

[Hooty]

Re: DESPERATE 1994 merc 150 EFI won't start (normally perfect)

Come on Willy, tell us what you really think about the aftermarket fuel lines. <br /><br />c/6<br />Hooty