Inancarrow
Cadet
- Joined
- Jan 15, 2002
- Messages
- 7
Hi Guys, help needed! A couple months ago my 4.3 V6 EFI has suddenly developed a fault, the engine always starts and runs without fault, idles well, hits full power etc etc. Until recently when you will be going along at cruising speed, anywhere between 2000-3500 RPM for up to half an hour, with no prior warning the engine will just drop all revs.. its stutters to a very low erratic idle bringing the boat off the plane and then usually stalls. The engine will usually start straight back up and go along fine again for another half hour or so before it does it again!
Now... on the odd occasion it has fully stopped and hydro locked, with it ingesting water into ALL cylinders, (both banks). Before you all say, I have removed and pressure checked the risers, compression checked the engine for head gaskets, removed and checked inlet manifold and replaced the exhaust flapper valves! Although it still seams to keep doing it!
Now is this a problem where by the engine is cutting out, due to a fuel/electrical problem and then water is shooting up the exhausts because off the rapid decent off the plane or.. is the water getting in first which is causing the engine to stall thus cut out and eventually lock.. however as I first stated.. it doesn't hydro lock every time, only 50% of the time of the stalls that are occuring.
I have also done all obvious checks, including fuel filter, fuel pump, spark plugs, replaced the ignition module under the dizzy cap, checked the anti syphon valve on the fuel tank and the battery voltage to the ECM, checked the stutter switch and the grey wire to the tach! I am generally pretty good with my fault finding but this has really got me baffled!
Any info or advice would be gratefully received! The engine is a Mercruiser 4.3 efi from around 2000, which we have retro fitted to a older style SeaRay running an alpha one, also the riser/manifolds are the rare 'all in one piece' swept design type if any of this makes any difference. Up until now we have had 2 years of hassle free boating from the whole outfit!
Cheers guys Ian
Now... on the odd occasion it has fully stopped and hydro locked, with it ingesting water into ALL cylinders, (both banks). Before you all say, I have removed and pressure checked the risers, compression checked the engine for head gaskets, removed and checked inlet manifold and replaced the exhaust flapper valves! Although it still seams to keep doing it!
Now is this a problem where by the engine is cutting out, due to a fuel/electrical problem and then water is shooting up the exhausts because off the rapid decent off the plane or.. is the water getting in first which is causing the engine to stall thus cut out and eventually lock.. however as I first stated.. it doesn't hydro lock every time, only 50% of the time of the stalls that are occuring.
I have also done all obvious checks, including fuel filter, fuel pump, spark plugs, replaced the ignition module under the dizzy cap, checked the anti syphon valve on the fuel tank and the battery voltage to the ECM, checked the stutter switch and the grey wire to the tach! I am generally pretty good with my fault finding but this has really got me baffled!
Any info or advice would be gratefully received! The engine is a Mercruiser 4.3 efi from around 2000, which we have retro fitted to a older style SeaRay running an alpha one, also the riser/manifolds are the rare 'all in one piece' swept design type if any of this makes any difference. Up until now we have had 2 years of hassle free boating from the whole outfit!
Cheers guys Ian
