Engine running badly
 

Hello, the Crusader 6.0 of my Mastercraft X45 is running badly.
At idle everything is ok and also if I increase the rpm, always at idle, the engine runs great.
The problem is when the engine is in forward gear and above 2000 rpm. Suddenly it starts to run not with full 8 cylinders but apparently wiht one or two less and after a while it turns off.
The fuel pump has just been replaced as well as the fuel filter.
Does anyone have any idea?

Check plugs and wires.

Plugs are new and the wires are ok.
If the problem was the plug and wires would not it be present also at idle?
In any case it is not unfortunately.

no necessarily. check distributor cap. cracks or moisture in it can create issues off idle that were at idle. what year is the engine?

The engine is a 2006 model

sounds like a fuel pump. may have 2 on that boat. check your fuel pressure when it stumbles.

Yes, the engine has two fuel pumps and both are brand new but I am going to check the fuel pressure.

with 2 new pumps and filters, should rule out any fuel pressure problems, since that was the last thing you had done I'd still confirm with a fuel pressure gauge.

another idea is sensors on the intake side, but I think I'd confirm stable fuel pressure first.

a friend of mine had the same issue. Boat would run fine up to about 25mph then start acting up. Had it in the shop for a long time trying to figure it out. When they replaced the plugs they didn't hook up the distributor cap correctly. Changed some wires around and it was fine.

proper firing order is a good thing!

Yes, I goin to check the pressure first and then the rest.
What I did not say is that the boat sank partially in the harbour and the engine is totally new as far as all the sensors is concerned, the wires, the plugs, the alternator, the fuel pumps, the collectors, all the filters and so on.
What has not been inspected yet are the injectors but it seems that they do not have problems.
The fuel tank has been totally washed, cleaned and no water is now inside.

so you've had an engine swap since it ran correctly?? take it back to whoever put it in and tell them your boat's f'd up.

at a minimum, take it to someone with a code reader and see what it says.

No, I did not have an engine swap, I only replaced all the electrical components that could go wrong after being submerged. The engine does not provide any error when the code reader is attached.
The engine buzzer does not sound and everything seems fine except when I increase the rpm. But also in this case the engine buzzer is silent, so no error is detected.
As said I am going to check the fuel pressure today or tomorrow and then we'll see.