1997 Merc 454 MIE cuts out and continues

[pete636ua]

I think this problem is electrical because it happens very quickly. The engine runs flawless most of the time - seems when warmed up and on plane it will cut out - yet not die. I have noticed the sync and tach gauges drop and then quickly resume. I have notice the problem occurs more above 3200 rpm. I have changed the coil, the ignition sensor in the distributor and it did nothing. Found a loose gray wire on the sync and tightened it - the problem seemed to go away for a couple of runs but it has now returned. Pulled the main engine connector and did not find any corrosion or anything that looked bad. I have tried removing the gray wires from the tach and the sync and there was no change. Also removed the gray wire going to the instruments at the coil and there was no change - still cut out. swaped ignition modules and there was no change - still cuts out yet will stay running. Has anyone had this problem? any ideas??

thank in advance!
Pete

 

[HT32BSX115]

Re: 1997 Merc 454 MIE cuts out and continues

Howdy,


Aside from testing the ignition system to determine if it is fact electrical, I would also have a look at fuel delivery. You could have a blocking problem from the fuel pickup all the way to the carb.

(fuel pick-up screen, anti-siphon valve, fuel pump, filter, carb, etc)


Regards,


Rick

 

[Fun Times]

Re: 1997 Merc 454 MIE cuts out and continues

You should try to separate the boat wire harness from the engine and just run the engine by hot wiring the engine.

That will help tell you if it's the engine or at the helm, You may need to do the same thing to the fuel line between the gas tank and the engine by running a portable fuel tank as a test.

Good luck with it.