2006 247 LSV Engine Rough

[christhesav]

I have a 2006 247 LSV. I have it up at Lake Tahoe (about 6,000 feet) and when I throttle above 3000 RPM the Engine starts to sound like it's misfiring. I have a high altitude Prop on it. I talked to a guy who suggested a new coil as he thought my year coil's had some known issues. I replaced the coil, distributor cap and rotor and it did not make a difference. It is not setting a Check Engine Light. I had a Malibu shop in Tahoe hook up a computer to it and they didn't see anything but convinced me to buy a new MAP sensor, which didn't fix anything... I have not noticed this issue at lakes closer to sea level. Any thoughts and help is greatly appreciated. Thanks in advance!

[REW]

Possibly an injector issue. Your computer is supposed to adjust the amount of fuel added to compensate for the lack of air at 6000' however if you have an injector that is leaking ever so slightly the adjustments may not be enough. This may manifest itself as a slightly rich cylinder at lower altitude, no miss fire.

Check your spark plugs to see if you have one that is wet or carbon coated. They should all be a slightly brownish ash color, boats do seem to build more carbon than a car/truck due to the cooler temps they operate at, however all 8 should match.

Good luck.

[christhesav]

Does anybody know the injector part numbers for this engine? It's the 383 Hammerhead