Why does my Voltage for my tps read 4.33 volts at WOT with the car off and only 3.4volts when actually flooring my car? I did two datalogs and still same results. Where could my problem be?

Verify that your TPS is installed properly in the slots of the throttle body.

Also make sure all your grounds, etc are secure.

Its on pretty tight and calibrated correctly. My grounds seem to be fine but you never know.

Try doing the TPS voltage test, with the car not running, and have someone push your accelerator pedal to the floor. It maybe your throttle cable or pedal that is the problem????

I don't see anywhere in Neptune that you can do a TPS calibration so I guess that is out of the question.

TPS Calibration is there as soon as you open preferences. That's the problem, he calibrated it with the car off and it's not running the same voltages with the car on.

Got it!



I'm so used to finding TPS calibrations in the start-up or in with the other sensor parameters.

Thinking about moving it.

So am I suppose to calibrate it with the car on or off?

It shouldn't be different.

Thats what I'm thinking, which leaves me at nothing then either buying a new tps and trying it out or something.

since the TPS is a simple potentiometer, if the WOT voltage changes from Koff to Kon it has to be one of a two things.... the 5V reference voltage lowers or the pot itself is bad.
(thought of ground offset but that would still result in the same voltage to the ECU)
Both are easy to check with a volt meter and a little wire.

You mean the tps is bad when you say Pot?

Does your datalog show that you are @ 100% throttle @ 3.4v?

"since the TPS is a simple potentiometer"
yep.

but if it's bad you should be able to watch the value with Koff and push in on the accel pedal slowly... the voltage will jump around and not be smoothly increasing.

I'll give it a whirl. Thanks

Tried it out the Voltage was smooth all the way through to WOT. So what can it be wiring?

looks like the pot seems ok... what about the 5V reference?

Havent looked at the 5V reference yet.

You'll want to test the reference with the car off and then on.