Fuel issues

[Henjan]

1991 Malibu euro f3 5.7 mercruiser.
Had a fuel issue. Engine runs fine for a while. Then quits. Cleaned brass fuel filter at carb and changed spin on filter. No change. Changed fuel pump. Worked fine for a while then quit again. Bypassed the spin on fuel filter and it runs fine. We changed a few spin on filters and dumped them out and fuel is clean. Is there something in the spin on housing that could be restricting fuel? Frustrated!!

 

[jimmbo]

Welcome to iboats

Perhaps the Vent for the Fuel Tank is plugged

 

[Henjan]

I checked that tonight and it is fine too.

 

[dingbat]

Just because there is no water or rocks in the filter doesn't mean that the filter media isn't clogged with sediment and debris.

Fuel filters should be changed annually. Have seen the filter media turn to mush after a couple of years

 

[Bondo]

1991 Malibu euro f3 5.7 mercruiser.
Had a fuel issue. Engine runs fine for a while. Then quits. Cleaned brass fuel filter at carb and changed spin on filter. No change. Changed fuel pump. Worked fine for a while then quit again. Bypassed the spin on fuel filter and it runs fine. We changed a few spin on filters and dumped them out and fuel is clean. Is there something in the spin on housing that could be restricting fuel? Frustrated!!

Ayuh,..... Welcome Aboard,.... Fuel filters are replaced, not cleaned,.....

 

[dubs283]

The water sep housing may have a restriction but it also could be drawing air

Quicksilver recalled this seasons crop of water seps cuz for some reason they decided to use an o ring seal instead of a quad ring. Still no update from merc so been using sierra brand water seps with the quad ring seal, no issues thus far

Another item to check would be fuel pressure and vacuum, especially under load.

Iirc many of the mie comp ski motors of this vintage used points ignition, perhaps tune up related?

 

[kenny nunez]

It could be the fine mesh filter that is in the suction tube in the tank. These things really can cause a problem. You will have to remove the fuel hose fitting that screws into the tank. The tube is screwed into the 90* elbow then you push the filter out and pitch it.

 

[Henjan]

Just because there is no water or rocks in the filter doesn't mean that the filter media isn't clogged with sediment and debris.

Fuel filters should be changed annually. Have seen the filter media turn to mush after a couple of years

We have tried 3 new fuel filters and know change. Thanks

 

[Henjan]

It could be the fine mesh filter that is in the suction tube in the tank. These things really can cause a problem. You will have to remove the fuel hose fitting that screws into the tank. The tube is screwed into the 90* elbow then you push the filter out and pitch it.

Thank you. Will have to check that. Didn’t know there was a filter in the tank as well.