Sorry in advance for the long winded report but I'm hoping the details add clarity and not confusion. I did search for other threads and found and read " [h=1]Mercury 2007 90HP 4-Stroke EFI Fuel Problem"[/h]
but the symptoms did not seem the same. Plus the mechanic did have fuel cannister apart (but may he missed a cracked hose?)
The short story... I have a (new to me this past june) 2012 115hp 4 stroke EFI merc outboard. After three failures the pattern that seems to exist is this.... if the motor is used for short runs (10-15 minutes) it will repeatedly start easy with no issues and run great. However, if I take it on an extended run (30-60 minutes), it will run great during the run but after I get it back to the dock it will begin to start hard and end up not starting at all after a period of time. Crank fine, but no start. There is 60 hours on the motor. Previous owner ( a friend) never had any issues since he bought it new. Gas had been stablized from the year before and topped up beginning of june. Fuel filters are new this year and installed correctly, etc. I'm not sure if the fuel pump is working correctly or not (see readings below) but the mechanic has not stated it is a problem. Problem may be getting progresively worse (hopefully something fails so it can be found).
Long story. I bought the boat and motor June30, 2016. For the month of july i did numerous short runs of a kilometer or less to local fishing holes and motor started fine each time I used it (turn key to on, fuel pumps runs for ~4 seconds and stops, turn key to start and motor starts easy after a second or two with no throttle required. Tach holds steady at ~800rpm) . Beginning of August I went for my first extended run (~60 minutes round trip) but stopped mid way for about two hours at a local island and then got back in the boat and returned home and no issues (motor ran great). Boat sits for the next week unused. When I go to start the motor after the week the motor cranks fine but no start. No sputter, no nothing. just crank. Since the EFI motor is new to me I did not have the knowledge to troubleshoot so, after checking the obvious stuff (that the kill switch was not activated, boat was in neutral, etc.), i took it to a merc authorized mechanic. Next weekend i go and pick it up and, while i had to prod the mechanic for details (so i may not have it exactly right), basically what he said was no trouble codes were found but it was gettting spark and no reason it should not be getting fuel and all fuses okay, etc. and he could not find a reason for it not to start. He eventually got it to run (by sparying gas into intake manifold?) and he takes it for a short run and all is good and it started fine the next couple of times he tried it during the rest of the week. He also said that fuel supply is a likely problem when efi motors don't start and,after i asked, he recommended i pick up a fuel pressure gauge to attach to the schraider value if the problem happened again (I bought a guage), So I pick up the boat from the mechanic, put it back in the water and took it for a short run around the bay (1km or so)... Started right away and ran great. Take it back to the dock and a couple of hours later i go on an 'extended' fishing run (~30 minute drive to spot) and it started right up and ran great going but, after fishing using the electric tolling motor for an hour or so, the motor started a bit hard (took maybe an extra second to start), But it did start and ran great back to the dock at all speeds, including up on plane and when moving through low speed zones. Once at the dock I shut it off and come back 30minutes? later and go to start and cranks but no start. Give it throttle and it starts hard and surges (correct term? tach needle, moving 1100-1200-1100). Try to start a couple of more times and eventually runs and smooths out. Shut off engine, put my new fuel pressure gauge in place... turn key to on and hear fuel pumps work and gauge goes to 51psi, when pumps stop and fuel pressure drops immediately to ~44psi and then bleeds down to 41psi over a period of 1-2 minute (not sure if this is normal or not). Start motor and fuel pressure gauge oscilates between 42-46psi with engine running smooth at 800rpm. Leave boat to next day, go to start, crank but no start. Took it back to the mechanic, no trouble codes, he pulled apart the fuel cannister (found a bit of debris but nothing he thought was an issue), pulled the fuel rail, tested the injectors, contacted Merc (no real help, just said to check the cannister float for sticking? and run through injector cleaner... which were done). Added an inline fuel water filter (not sure if it would help but though it couldn' hurt). Note that the sponge of the intake filter has degraded and some small holes in it (will be replacing with the stainless steel version... $131 CDN!). I'm sure the mechanic did more stuff, and not sure what did the trick, but after all the work was done by mechanic he got it started and it ran fine again. mechanic started several more times during the week he had it and all times it started okay (but no test drive, just start and stop) Next weekend I pick it up, back in the water, take it for a short run around the bay and runs great and return to the dock. Must be fixed, right? 30 minutes later boat starts fine and I take some friends out for an extended 45-60 minute run... boat runs great at all speeds. then we then stop and anchor the boat for 30 minutes to go swimming, then go to start boat and hard start, but does start after two attempts and runs great back to the dock, but then the longer it sits at the dock the harder to start, runs rough, and after letting it sit for an hour or so, no start no matter what i did. I install the fuel pressure gauge... this time pressure only builds to ~49psi, and not 51psi like first time (is it real or just gauge inaccuracy? does it matter?), drops to 44psi as soon as fuel pump stops, bleeds down to ~40 psi after a couple of minutes but seems to hold at 40psi but i have never checked longer than a couple of minutes (I don't know what is considered acceptable... i have ordered a merc service manual but not in yet). Motor would, however, kick over for an instant if I sprayed gas from a WD40 bottle in the intake manifold with the throttle open to allow the gas to enter the manifold but just kick over for the instant and then only crank. Began to wonder if the motor might start the next day after the motor has cooled down (though maybe motor heat from the extended run was impacting a sensor???... note that motor was only warm to touch) but 14 hours later, still only crank with no start. Took the boat back to the mechanic and he tried and still crank no start. He again hooked it up to computer and again no trouble codes (just low battery from my attempts to start). He said he had some more ideas to check but was short on details. $$$ are adding up. Any help would be appreciated.
but the symptoms did not seem the same. Plus the mechanic did have fuel cannister apart (but may he missed a cracked hose?)
The short story... I have a (new to me this past june) 2012 115hp 4 stroke EFI merc outboard. After three failures the pattern that seems to exist is this.... if the motor is used for short runs (10-15 minutes) it will repeatedly start easy with no issues and run great. However, if I take it on an extended run (30-60 minutes), it will run great during the run but after I get it back to the dock it will begin to start hard and end up not starting at all after a period of time. Crank fine, but no start. There is 60 hours on the motor. Previous owner ( a friend) never had any issues since he bought it new. Gas had been stablized from the year before and topped up beginning of june. Fuel filters are new this year and installed correctly, etc. I'm not sure if the fuel pump is working correctly or not (see readings below) but the mechanic has not stated it is a problem. Problem may be getting progresively worse (hopefully something fails so it can be found).
Long story. I bought the boat and motor June30, 2016. For the month of july i did numerous short runs of a kilometer or less to local fishing holes and motor started fine each time I used it (turn key to on, fuel pumps runs for ~4 seconds and stops, turn key to start and motor starts easy after a second or two with no throttle required. Tach holds steady at ~800rpm) . Beginning of August I went for my first extended run (~60 minutes round trip) but stopped mid way for about two hours at a local island and then got back in the boat and returned home and no issues (motor ran great). Boat sits for the next week unused. When I go to start the motor after the week the motor cranks fine but no start. No sputter, no nothing. just crank. Since the EFI motor is new to me I did not have the knowledge to troubleshoot so, after checking the obvious stuff (that the kill switch was not activated, boat was in neutral, etc.), i took it to a merc authorized mechanic. Next weekend i go and pick it up and, while i had to prod the mechanic for details (so i may not have it exactly right), basically what he said was no trouble codes were found but it was gettting spark and no reason it should not be getting fuel and all fuses okay, etc. and he could not find a reason for it not to start. He eventually got it to run (by sparying gas into intake manifold?) and he takes it for a short run and all is good and it started fine the next couple of times he tried it during the rest of the week. He also said that fuel supply is a likely problem when efi motors don't start and,after i asked, he recommended i pick up a fuel pressure gauge to attach to the schraider value if the problem happened again (I bought a guage), So I pick up the boat from the mechanic, put it back in the water and took it for a short run around the bay (1km or so)... Started right away and ran great. Take it back to the dock and a couple of hours later i go on an 'extended' fishing run (~30 minute drive to spot) and it started right up and ran great going but, after fishing using the electric tolling motor for an hour or so, the motor started a bit hard (took maybe an extra second to start), But it did start and ran great back to the dock at all speeds, including up on plane and when moving through low speed zones. Once at the dock I shut it off and come back 30minutes? later and go to start and cranks but no start. Give it throttle and it starts hard and surges (correct term? tach needle, moving 1100-1200-1100). Try to start a couple of more times and eventually runs and smooths out. Shut off engine, put my new fuel pressure gauge in place... turn key to on and hear fuel pumps work and gauge goes to 51psi, when pumps stop and fuel pressure drops immediately to ~44psi and then bleeds down to 41psi over a period of 1-2 minute (not sure if this is normal or not). Start motor and fuel pressure gauge oscilates between 42-46psi with engine running smooth at 800rpm. Leave boat to next day, go to start, crank but no start. Took it back to the mechanic, no trouble codes, he pulled apart the fuel cannister (found a bit of debris but nothing he thought was an issue), pulled the fuel rail, tested the injectors, contacted Merc (no real help, just said to check the cannister float for sticking? and run through injector cleaner... which were done). Added an inline fuel water filter (not sure if it would help but though it couldn' hurt). Note that the sponge of the intake filter has degraded and some small holes in it (will be replacing with the stainless steel version... $131 CDN!). I'm sure the mechanic did more stuff, and not sure what did the trick, but after all the work was done by mechanic he got it started and it ran fine again. mechanic started several more times during the week he had it and all times it started okay (but no test drive, just start and stop) Next weekend I pick it up, back in the water, take it for a short run around the bay and runs great and return to the dock. Must be fixed, right? 30 minutes later boat starts fine and I take some friends out for an extended 45-60 minute run... boat runs great at all speeds. then we then stop and anchor the boat for 30 minutes to go swimming, then go to start boat and hard start, but does start after two attempts and runs great back to the dock, but then the longer it sits at the dock the harder to start, runs rough, and after letting it sit for an hour or so, no start no matter what i did. I install the fuel pressure gauge... this time pressure only builds to ~49psi, and not 51psi like first time (is it real or just gauge inaccuracy? does it matter?), drops to 44psi as soon as fuel pump stops, bleeds down to ~40 psi after a couple of minutes but seems to hold at 40psi but i have never checked longer than a couple of minutes (I don't know what is considered acceptable... i have ordered a merc service manual but not in yet). Motor would, however, kick over for an instant if I sprayed gas from a WD40 bottle in the intake manifold with the throttle open to allow the gas to enter the manifold but just kick over for the instant and then only crank. Began to wonder if the motor might start the next day after the motor has cooled down (though maybe motor heat from the extended run was impacting a sensor???... note that motor was only warm to touch) but 14 hours later, still only crank with no start. Took the boat back to the mechanic and he tried and still crank no start. He again hooked it up to computer and again no trouble codes (just low battery from my attempts to start). He said he had some more ideas to check but was short on details. $$$ are adding up. Any help would be appreciated.
