More GT-40 Troubles

[1998CanadaNautique]

My 1998 Nautique GT-40 EFI is giving me grief. When I run it at 4000 RPM or over it will cut out for half a second then go again at full speed. And a minute later it will do it again. Anything I can try.

[Rick]

RE: More GT-40 Troubles

Fuel injection cleaner, Fresh High Octane gas. If that fails I would get a pressure guage that attaches to the fuel rail (SKIDIM) and check to see that you are getting a continuous 35PSI at the rail. The 2 major causes of fuel starvation is bad low pressure fuerl pump and less likely high pressure fuel pump.

[DanielC]

RE: More GT-40 Troubles

Step one in diagnosing ANY driveability problems with a marine fuel injection engine is to check the fuel pressure. There is no feedback from the engine to the computer that controls the injectors. The computer just senses rpm, barometric pressure, engine load, throttle position, coolant temperature, air temperature, and some other parameters I might of forgot. The computer then assumes the fuel pressure is correct, and controls the injectors to open the right amount of time.

[swooddc]

RE: More GT-40 Troubles

Gt40s don't need or like high octane, save the money. Rick is right on everything else. mine was doing something very similar. I had a clogged fuel pickup, bad low pressure pump, bad injector pump. I am pretty sure I lost the pumps because the clogged pickup made the pumps suck air.