7.4mpi just started running rough and with gas coming out exhaust

[alldodge]

I'm out of town so don't have access to manuals. Will look upon return and post info. Maybe @achris has pin outs or wiring and can assist

 

[Ozshadow]

Anything to make sure injectors themselves are not a problem other than measuring resistance?
Looks like I will be getting a mefi4 with the conversion harness.

 

[alldodge]

Would not be able to make that decision. My self i would have them cleaned and flow tested at a place that does marine

 

[achris]

By your serial number you should have MEFI3, here's the MEFI3 wiring diagrams and ECU pinouts.



Bit closer shot of the injector harness.


I have attached the relevant pages from the manual on the MEFI3 pinouts and circuit descriptions.

Chris......

 

[Ozshadow]

New ECM is in. The mefi4 with the adaptor harness from OBD. Boat seems to run good but the power curve feels slightly different. Nothing anyone except me would notice.

I need to change the oil again to be safe. I’m sure plenty washed down from my testing.

I have to repair one of the three throttle body bolts. It wouldn’t snug up. I guess a heli-coil for this? I probably should have checked the bolt size. I feel like this one was a metric.

End of season will be a new thermostat. Mine must be stuck open. It’s staying at 130.

My #1 battery died. 7 years was a good run. It even stayed in the boat every Michigan winter, just disconnected.

Maybe I’ll eventually get to enjoy the boat this year.

Thanks everyone for all the help.

 

[alldodge]

Heli coil will work if needed
Verify temp at thermostat housing with IR temp gun

Good to hear your up and running

 

[nola mike]

I have to repair one of the three throttle body bolts. It wouldn’t snug up. I guess a heli-coil for this? I probably should have checked the bolt size. I feel like this one was a metric.

Don't know what the TB looks like on that, but I had the screws snap on my distributor for the cap. Was about to go helicoil route when I realized i could just drill straight through and use a screw with a nut on the other end

 

[Ozshadow]

Sure glad I changed the oil. I had about 3 qts more than I should have. At least I started with straight 40w.