2003 Gibson Houseboat with 496 8.1 Vortec Fuel Injected Engines. Marinized by Marine Power in Louisiana.

Port Engine quits running at 3200 RPM. We have changed low and high pressure fuel pumps.

We have cleaned fuel vent hole.

Nothing seems to work.

further testing is needed and a proper scan tool to read all the parameters especially when it stalls... This should have MEFI 4 for a controller.

I would run the boat a remote fuel tank and new fuel line with a primer bulb. work the primer bulb if the engines sounds like its going to stall. I understand you put new fuel pumps in but that does not mean anything -- did you change the fuel pressure regulator as well ?? . What is your fuel pressure readings thru out even when it stalls ??

What is your voltage readings when the engine stalls ??

What is your 5 V reference reading when running and when the engine stalls ?

My guess is crank sensor but only guess here ------------- impossible to truly fix a boat over a forum with very little info plus many are not going to know how a Marine power 8.1 is set up.

does this engine restart right away or the next day or never restarts.??? A lot more info is needed on your end cause the post you have will be huge dart throwing. contest plus this engine is not set up like a Mercruiser period. .

I have worked on many marine power apps in the past all the 350 s and all the big blocks. really do not see them anymore. thou.