Limp mode issues please help.

[Lvnspeed]

I have a 2000 Air Nautique with a GT 40 motor. Boat runs great for about 20-30 minutes above 2500 -3500 rpm then it goes into limp mode.
No check engine lite
Good oil PSI 50- 60 psi
Water temp is about 150
new cap and rotor
new plug wires
new motor
Shut off the motor then start it back up and it runs fine.
I unhooked the the oil PSI switch no change. So I hooked it back up.

Any ideas? I have read that it could be the oil PSI switch, water switch (where is it?), or it could be some manifold switch (where is it?) Can anyone tell me the the part numbers?

[Lvnspeed]

anyone?

[bscott]

I believe the oil press and temp switches are the only two things that will cause it to go into limp mode, and the check engine light normally lights when in limp mode.

The temp switch has a tan/black wire just like the oil press switch. Looking at the front of the engine, the temp switch is on the top left side.

Check out the GT-40 service manual. Limp mode is referred to as SLOW.

[Lvnspeed]

Still fighting the Limp mode or Slow mode. Is it possible to run the motor with the knock sensor removed or unplugged?

I have the mentioned sensors unplugged and I am still getting a limp mode only when I run the boat at 3000 rpms or higher for more than a 1/2 hour like crusing accross the lake. Any more suggestions?

[bobchris]

I have a 2000 Air Nautique with a GT 40 motor. Boat runs great for about 20-30 minutes above 2500 -3500 rpm then it goes into limp mode.
No check engine lite
Good oil PSI 50- 60 psi
Water temp is about 150
new cap and rotor
new plug wires
new motor
Shut off the motor then start it back up and it runs fine.
I unhooked the the oil PSI switch no change. So I hooked it back up.

Any ideas? I have read that it could be the oil PSI switch, water switch (where is it?), or it could be some manifold switch (where is it?) Can anyone tell me the the part numbers?

you unhooked the sending unit for the gauge and not the switch for the computer like you should have.

[Lvnspeed]

you unhooked the sending unit for the gauge and not the switch for the computer like you should have.

I dont think I unhooked the wrong ones I still saw oil PSI on the guage and still saw water temp.

Can I unhook the knock sensor and still run the boat?

[tldreyer]

My first Nautique was a 1996 (I think) SNOB. I have a **** of a time with limp mode at one point - trying to find out what was setting it off. Turned out to be the main unit - bascially a computer, I believe, and not any one sensor. Hope this helps and hope you figure it out.....it is no fun, I know.

[waketherapy]

mine did the same thing, it was the crank angle sensor, same issues and everything