I have a 502 EFI with M1 Procharger on it.
I was running it with plugged valve cover breather tubes.
Subsequently the crank pressurized and the oil pumped out.
After replacing the oil, putting in new plugs and replacing the Map Sensor, the engine still seems to be using an excessive amount of gas.
So much gas that I get a black layer of unburned fuel behind the boat.
Any ideas as to the cause?

What temps are you seeing on your water temp gage? Does not seem to me that it would be related to the lack of crankcase ventilation. Feels like a coolant sensor out of range.

BT

what's your fuel pressure?

fouled injectors?

BLUE THUNDER.
I was talking to Mark at Precision Marine and he was of the same opinion , that the temp sensor might be bad.
He also went on to say that the VST tank might have some junk in it causing the last 2 cylinders to receive to much fuel.

Dixie Doug - The Fuel Pressure on the Gage is showing 50 at first ignition and between 40 and 45 when idling.

fuel pressure should be 30-34 @ idle

Doug. is this with the ProCharger as well that it should be this low?

that is according to ProCharger specs

Thanks Doug,
I'll set the regs back and try that.

Let us know how you make out. I'd think 30% extra pressure would equal to 30% extra fuel and a lot of unburned fuel. Good luck.

BT