Idle Issue on 2001 2700 SCR

[Simon Apex Antill]

Hi guys,

So happy I found a Maxum owners club forum! Any help with my super irritating idle issue with my 2001 Maxum 2700 SCR would be amazing! I love my boat but this year I had an alternator die on me and when limping the boat back to the marina with a non functioning alternator the boat died, misfired and made a whole bunch of weird noises. I replaced the alternator and ever since the boat has had an idle issue going in and out of gear. Basically if I knock it into forward or reverse with out feathering the throttle she dies. I have replaced the IAC valve, every sensor on the motor, checked for vacuum leaks but the problem persists I have had several Mercruiser techs look at the boat, plug it into a laptop etc and everyone is scratching there heads. The last tech suggested that the power outage on the boat may have done something to the ECM on the boat. Has anyone else experienced any challenge similar? My boat has a Mercruiser 7.4l mpi with a Bravo 3 outdrive. The strange thing is the boat purrs like a kitten everywhere but idle! When I drop her into forward or reverse you can hear the motor suck air and its almost like it chokes itself out. Any help would be beyond appreciated

Thanks

Simon

[mmwjr]

First welcome aboard.

When the alternator failed why did you have to limp home? The engine should have ran until the battery got low.

Did the alternator lock up, break the belt? If so did the engine overheat?

[Simon Apex Antill]

Originally Posted by mmwjr

First welcome aboard.

When the alternator failed why did you have to limp home? The engine should have ran until the battery got low.

Did the alternator lock up, break the belt? If so did the engine overheat?

Thanks buddy So happy to find more Maxum owners

In a nut shell I was limping back because I had been out over night and the batteries were super low. I wasn't in limp mode just moving slow. I got half way back when the batteries went totally dead and the boat died. No belts broke, no over heating just went kapoot when the batteries got to low to run the boat

This idle issue has me pulling my hair out. Is it poss to get an ECM reset or re flashed to factory?

Thanks

Simon

[mmwjr]

I do not think low voltage should cause damage to the ECM, however an over voltage may but I cannot think how it wold impact idle only.

Did you fully recharge the batteries, load test them? Are they deep cycle?
If the batteries were damaged they can act as a load to the alternator which causes it to work harder and may result in low rpms at idle.

Is you mechanic Merc certified? If so he should know if the ECM can be flashed but to my knowledge it cannot. You may also want to contact merc and ask them.