Acu

[wzguy]

Injectors not firing on my older 260 that I have been piecing togeather. Went from analog box to digital acu. Any help please

[Jay Smith]

​Check key switch harness cannon plug , make sure key switch purple is hot !

[tripower]

Had this problem with my ACU when the big plug on the ACU came loose. At least on my boat, it doesn't thread together like the stock ECU connector did so it can work loose. It looked connected but the injectors weren't all firing.

[wzguy]

Jay I have spark . Tripower that plug does not seem to go all the way togeather. Thanks more stuff to check leo

[Mrzip]

. ACU Is Confused. Call For Juice. New Battery. @ Least Group 27.

[Jay Smith]

Could be injector harness , do you have another you can switch out ? Also most Mercury Outboards can have issues with “6pack” style optima battery’s hopefully your using a deep cell Marine battery like interstate 1000 cranking amps ...
Also there is a red jumper that goes from positive on rectifier to hot side of starter sylinoid that main inlet from battery connects AND a red wire jumps from there to ECU harness make sure those are all in good shape ...


Jay

[wzguy]

Mrzip this boat has three batt. Main one is like garden tractor size says Braill on top an agm. That is hook with another batt motorcycle. Size says 180 cca gel on it they both check 12.6 12.4 volts I have 1000 cca in my action I could try if you think I need to. Jay have no way to check harness purple wire has 12.4 volts . There is no jump wire from solenoid to rectifier but both those red wires have power when batt on. This is ex race boat I would think everything in boat is good. Thanks for the input leo

[Jay Smith]

I checked I have a drag and a 260 here I’m building there IS a jumper wire from + side of the rectifier to the hot side of the starter syloid where + side of the battery is connected , there is also a red wire connected there that powers ECU harness , without that wire that jumps from rectifier the stator can’t charge battery ...Check on rectifier that is marked + must jump to point where + battery terminal attaches or charging can’t happen ..

Jay

[Mrzip]

That ACU Really Has To Have Constant Power. Better The Reserve In The Cranking Battery. Better it will respond. Just My Personal Experience

[wzguy]

Thanks for the help guys .put new stator an trigger on fired right up. Thanks leo