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...
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.
How should I test the harness with a multimeter from the injector to the ECM connector to be absolutely certain I don’t have something that will cause a problem for the new $2500 ECM?
All injectors read 12.9 resistance from what I recall - all were the same.
I am just second guessing...
FINAL UPDATE - fried injector driver. Not repairable.
How difficult is removing the entire harness between the ECM and injectors? I know the short injector harness come off easily. I want to look at every inch of wire before I put in a $$$ ECM.
I think this post explains what we we all missing. See #5 by John Marzetti of Boats Unlimited. My engine is an L29.
https://www.offshoreonly.com/forums/general-q/332476-7-4l-mpi-wont-start.html#post4376566
He explains the unique injector banks.
The only other thing I can think of is the opposite side of the ECM - not the wires going to the injectors. Maybe a pin isn’t being powered or receiving full power? Maybe a relay?
I will send it to OBD. I know the banks fire in a different order but the odd side holds 12v on both injector leads until it grounds and fires.
The even side is 12v on the power side and 8v on the ECM side which makes it act sorta like a ground. The noid light is on solid but dim. All it...
My injector plugs are numbered and connected correctly. 2, 4, 6 and 8 on the starboard side.
I will see if the voltage readings ever change.
I will also look to see if any colors match. Maybe the banks are really different than just evens and odds. The spark plugs were definitely only...
I think the L29 fires all evens and all odds doesn’t it?
I am particularly focused on why the voltage on the even side wires from the ECM is almost 5v lower when only the key is on. That is a unique voltage drop.
