ECU problems

[Scubadiver#1]

Is it possible to update ECU software on Volvo penta KAD44P A. I have an ECU which has an intermittent fault. Engine will not rev past 2800rpm, maximum is 3800 . Could the software be the problem.

 

[QBhoy]

Hi. Is this when it’s in gear and underway? Did it previously perform better ?
If she used to be ok and this is a recent issue not caused by any intervention with props or elsewhere, the most common reason for such a thing on a kad would be because of a turbo failure or supercharger issue. Is the charger operating properly? Is it on load from low rpms and then cutting off when the turbo takes over mid rpm range ? Or is it cutting back in or staying engaged longer than it should ? Any sign of black smoke out the back or soot in the engine bay ? Exhaust elbows suffer corrosion issues too. Any faults on the dash ?

 

[Scubadiver#1]

Thanks for you reply.
The problem occurs when we accelerate to get on the plan. Supercharger cuts in at 1700 rpm and cuts out at 2800 all seems good to this point. When the supercharger cuts out, the revs drop back until the supercharger engages again . We get a surging effect and the enging will not rev past 2800 rpm.
No black smoke. We have replaced exhaust elbow, turbo and fuel filters. No faults are shown in diagnostic mode.
When the fault does not occur, the engine runs perfectly and revs to 3800. Could it be a fuel shortage from the ECU after 2800rpm. The fault almost never occurs on the first run out of the marina but almost always when we run on the second day of a trip. As I said before, it is an intermittent fault and if we change the ECU to the other enging , the fault follow. That's why I suspect the ECU. Though any ideas would be helpful.