1999 Ski w/ GT40 Hesitation over 2500 RPM's

[Johnsongc]

A friend of mine is having a frustrating problem:

After approx 5 minutes of completely normal operations the engine stops performing above 2500 rpm's. In essence it lurches and will not continue to power through. Seems to operate fine a lower than 2500

Fuel Pumps and filter have been replace. Engine temps are normal, but could this have something to do with the "limp mode" possibly falsely engaging?

Any thoughts are greatly appreciated.

Thanks,

Greg

[NautiqueJeff]

RE: 1999 Ski w/ GT40 Hesitation over 2500 RPM

Sounds like limp mode to me. How's the oil pressure? Is the red light on?

[maioman]

RE: 1999 Ski w/ GT40 Hesitation over 2500 RPM

I am having the exact issue.. Red light is on, oil and temp read fine on the dash guages, but it is in limp mode.. I ordered new oil and temp senders from skidim.com and was instructed to clean the ECU connector.. I will keep you posed.. I have a 1997 SN..

-Chris

[ag4ever]

RE: 1999 Ski w/ GT40 Hesitation over 2500 RPM

I had my oil pressure sensor go out, and caused this. I believe, I just disconnected it and the boat ran fine. I think the sensor ground the circuit under a certain pressure level. Above that level it opens and tells the ecu that all is OK. If you do that be sure to keep an eye on the oil pressure guage which should use a different sensor.

[Johnsongc]

RE: 1999 Ski w/ GT40 Hesitation over 2500 RPM

Unknown on the oil pressure, but will check. The engine light is coming on while the engine is malfunctioning. Where is the oil sensor? I think I know where the temp is, but will ask anyway? Thanks for the help!!

Greg

[DavidF]

RE: 1999 Ski w/ GT40 Hesitation over 2500 RPM

I believe the oil pressure switch is teed off the tube feeding the oil pressure sending unit. Bottom left (port) front side of engine near the oil filter.

[Johnsongc]

RE: 1999 Ski w/ GT40 Hesitation over 2500 RPM

It turned out to be the coolant temp sensor. We disconnected and the "limp mode" went away. Now just have to figure out if it a failed sensor or a bad ground somewhere.

Greg