Throttle position sensor

[brad]

I have a 2001 air with the GT-40 and it has developed a problem between 600 and 1200 rpm where the engine surges out of that range it runs perfectly, could it be a problem with the TPS

[core-rider]

RE: Throttle position sensor

It's possible the TPS could cause this, but I would look at the IAC (Idle Air Control) motor first. It will be the cylinder mounted on the side of the thottle body with 2 wires plugged in at one end. They can get dirty from carbon and oil deposits building up and causing the valve to stick. Remove the IAC assembly and take the motor off the end. Then clean the housing with carburator cleaner until the black deposits are gone. Should take care of it.

You can test the voltage of the TPS between the orange and black wires I think. You should read 0.99 VDC. If it is out of range more than 0.05 VDC it may need to be adjusted or replaced. But try the IAC first.

[brad]

I have already changed the IAC and it made no difference what so ever, also i changed plugs leads fuel filter all the basic things, and summer is fast approaching

[core-rider]

If you have already tried the IAC then I guess look at the voltage of the TPS. I've already given you the specs... I really don't think that will be it though. You may want to try looking at things like vaccume leaks as well, but usually they will just cause high idle or the engine to shut off.

[brad]

Thanks for your help ill test the voltage today, i dont really think it can be anything but that. i had the same problems at idle in my ute and it was a faulty tps so fingers crossed

[1999Sport]

Download the GT40 manual from this site. Section 3E7 (page 3E-43) has a troubleshooting procedure on the TPS. The voltage is on a linear scale, so as the throttle opens more, the voltage at the TPS will increase. If there are any spikes in the voltage, or the voltage doesn't change at all...you have a bad TPS, $50 later....you'll be back on the water....good luck