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Ask Dominick Your Own Question
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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I have a volvo penta 5.7gi problem. Engine has about 450 hours, but sat over the winter w

Customer Question

I have a volvo penta 5.7gi problem. Engine has about 450 hours, but sat over the winter with water dripping on back of engine and cold temps. Fuel filters were changed and had water in them. Not sure if enough to get into fuel injection.
Engine idles fine and not under power will rev to 4000-5000 without problem. Under load engine runs up to around 2000rpm fine then timing falls apart, engine starts knocking, valve clatter, and loss of power. Replaced two sensors and checked ECM. ECM I swapped out with my other engine and problem stayed the same. Under power over 2000rpm engine timing is all over the place.
Submitted: 2 years ago.
Category: Boat
Expert:  Jason replied 2 years ago.
Hello my name is ***** ***** am I speaking with? Have you run this engine off of another fuel supply yet?Is the oil level high on the engine?
Customer: replied 2 years ago.
Thanks Jason, my name is David. The boat has two engines and two fuel tanks. One engine runs fine from either tank, the other has this problem from either tank. Each engine has a large filter/separator and then a filter separator on the engine itself. Oil level is not high.
Expert:  Jason replied 2 years ago.
Have you measured fuel pressure while underway, if so, what does it read?
Customer: replied 2 years ago.
Havent measured fuel pressure. fuel filters have been replaced. Two sensors have been replaced. ECMs were switched between engines and problem unchanged. Out of gear engine revs normally, in gear engine bogs and clatters over 2200 rpms. Timing scope shows timing falls apart at 2200 under load and jumps all over the place. Problem started after boat sitting for the winter. Last fall engine ran fine.
Customer: replied 2 years ago.
TPS and MAP sensors have not been changed
Expert:  Jason replied 2 years ago.
Compression and fuel pressure are going to be the first 2 sets of checks before getting into the EFI system. Did you want to do those and get back to me?
Customer: replied 2 years ago.
ok, thanks
Expert:  Jason replied 2 years ago.
You bet, keep me posted.

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