intermittent stalling

[33 Proud]

I have the 5424 Universal engine and I am having problems with it running perfectly sometimes and other times it stalls or will runs at idle but will not increase in RPMs when I give it more throttle.

The mechanic said it was a clogged fuel filter. He changed that but said that the old filter was not very dirty and that the fuel looked clean. Anyway, after this work the engine would not start for him. He had another mechanic come out to look at the injector pump but before this mechanic looked at the pump he tried the engine and it started right up. He ran it for an hour or so and it never failed. The next weekend I tried it and it ran for 20 seconds and sputtered out. The mechcanic goes out again and it works fine for him. I have the mechanic replace the old, worn out fuel lines and he does so and the engine runs fine for him. The next weekend it sputters for me and dies out.

Can the Walbro fuel pump work intermittently? I turned the ignition key to on and opened the bleeding valve on the Racor filter but the Walbro pump did not come on. A little fuel dripped out of the bleeding valve. I did this a few times and one time. after several seconds of dripping, the fuel pump came on and the fuel squirted out of the bleeding valve as it should.

The mechanic is telling me it is my injector pump not the Walbro pump. Can an injector pump work great sometimes and not at all other times? Can an electric fuel pump work sometimes and not others?

[Ed Haley]

When you say the engine didn't start, did the engine crank over but did not fire up? Or did it not crank at all. If it didn't crank at all, there may be a faulty ground wire going to your engine specifically the ground wire attached to a plate that is on the starboard side of the engine. It may be a bad ground elsewhere but check there first. That plate may even be cracked.

If the engine cranks fine but doesn't start and when running, it sputters, I would suspect a fuel problem - there may be gasoline or other contaminant in your fuel.

Good luck.

[33 Proud]

It would crank very well. Sometimes the engine would sputter, other times it would just not start at all and sometimes it would work great. I think the Walbro electric fuel pump is going out since it seems to turn on sometimes and not other times. The last couple of months I could hear the electric pump come on for a couple of seconds when I turned the ignition key. Recently it would hear it come on continuously and other times I would not hear it at all. David

[Stan W.]

If you still have one, throw it away.

[VidaliA]

Try replacing your ignition switch. It could be a faulty wire sometimes making the connection. I had this problem and it was just the switch and very inexpensive to rule out.

[Chris Reinke]

I had a similar problem with my M-30. I replaced all the filters and had fuel flowing....but did not realize it was flowing slow. The engine would run fine for hours, and other times die after just a few minutes. It would occasionally re-start but only maintain an idle. If I tried to increase RPM's it would stall.

It turns out I had a glob (I know this is not a technical term...but it was a glob) of condensed fuel that would migrate around in my tank. Once it got sucked over the fuel intake the engine would stall. Cranking would not start it again until the glob floated away from the intake hose.

I drained the tank of fuel and sucked out all the debris that had settled in the bottom of the tank over the last 20 years....it was kind of nasty. Once I had the tank clean...some new fuel...no more problems.

[Steve Laume]

not electrical. I have seen the glob of gunk in my tank. It was about the size of a mouse and could easily slosh over and plug your fuel intake. That may be the case but it sounds like you're suspitious of the fuel pump. When I changed to a Racor filter right after I bought my boat I also installed a vacuum gauge downstream of the filter. The idea is that if the fuel pump is drawing a vacuum then the filter is clogged and it is time to change it. If you had this set up on your boat I think you would be well on your way to trouble shooting your problem. If you looked at the gauge and it showed a vacuum then you have an obstruction. If you just changed the filter then that is unlikely to be the problem. If you pulled the hose off at the tank and it went away you could figure it was the pick up. If you are not drawing a vacuum and close the fuel valve at the tank it should. If it doesn't then it is the fuel pump. You might not know why the fuel pump doesn't work but at least you would know where to concentrate your search. I think the vacuum gauge set up cost me a TEE and about $50.00 for the gauge. It has yet to register and is saving me money on unessiscary filter changes, Steve.