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New Member
2002 Sea Ray 380 w/8.1 Horizons. W/Gen 2 cool fuel module.
My Port engine won't maintain cruising RPM (3,200-3,400 RPM) after about 2-2.5 hours of cruising. It acts like it wants to stall and sputters and drops to idle speed (900 rpm) but never actually stalls. If I shut engine down for 5-10 min it will start fine and runs fine for another 1/2 hour or so. It has happened 4 times in the past 2 years and only on long cruising runs. I have changed water sep filters multiple times and last gas sample showed no signs of moisture in fuel.
I'm starting to think it is some kind of heat build up issue, since it always happens about 2+ hours in to a long run. (All engine temp gages on the dash read normal)
Last week I got almost to 3 hours by varying my RPM every half hour or so 3,600, then down to 3,200 then 3,800 back to 3,000 etc, and I also ran my blower the entire time. Also Fuel gages all seem to be between 1/2 to 1/4 when it happens. Fuel Pick up line??? Mercruiser support says to do a fuel pressure test when it happens. But ,well, how do I do that when I never know when it is going to happen??? ;-)
My Mechanic is backlogged on work but I'm trying to get as much info I can to help diagnose.
Any thoughts GREATLY appreciated!
My Port engine won't maintain cruising RPM (3,200-3,400 RPM) after about 2-2.5 hours of cruising. It acts like it wants to stall and sputters and drops to idle speed (900 rpm) but never actually stalls. If I shut engine down for 5-10 min it will start fine and runs fine for another 1/2 hour or so. It has happened 4 times in the past 2 years and only on long cruising runs. I have changed water sep filters multiple times and last gas sample showed no signs of moisture in fuel.
I'm starting to think it is some kind of heat build up issue, since it always happens about 2+ hours in to a long run. (All engine temp gages on the dash read normal)
Last week I got almost to 3 hours by varying my RPM every half hour or so 3,600, then down to 3,200 then 3,800 back to 3,000 etc, and I also ran my blower the entire time. Also Fuel gages all seem to be between 1/2 to 1/4 when it happens. Fuel Pick up line??? Mercruiser support says to do a fuel pressure test when it happens. But ,well, how do I do that when I never know when it is going to happen??? ;-)
My Mechanic is backlogged on work but I'm trying to get as much info I can to help diagnose.
Any thoughts GREATLY appreciated!