Thread: TPS is bad?

My TPS is only reading 3.25 volts on my voltmeter at WOT. Is that normal? I thought it was supposed to be 5volts at WOT Car is a 1998 200sx SE-R. Will adjusting the TPS help? I think its somewhat tilted back but i have not been able to find a screwdriver short enough to loosen the 2 bolts. As soon as I do ill move it.

Unless of course it wont do anything and my TPS is bad. Any help will be appreciated.

If it's a newer tps, an 8mm wrench does the trick. If not, use a phillips head socket instead of a screwdriver to get it off. And to answer you question, yes, it is possible to turn it quite a bit to adjust, but that's a lot. Adjust it first, answer your question for free, then look at replacement

Not sure about your car but heres the TPS adjustment instructions:

At WOT, and your TPS is only reading 3.25v THEN.....
Adjust the throttle screw out (turn to left very slowly) until the TPS reads 4.0v EXACTLY ! !

With closed Throttle ONLY will you need to adjust the screws on the TPS itself...
At Fully CLOSED Throttle, your TPS should read between 0.45v and 0.55v. Get it as close to 0.45v as you can.

To determine if TPS is bad, perform and Ohm test:
(Unplug TPS, with the plug clip facing up, the left pin = Terminal A and middle Terminal pin = B)
- Test resistance between Terminals A & B
- Completely released - Approx 2 ohm
- Partially released - 2 - 11 ohm
- Completely depressed - Approx 11 ohm
If not, the TPS is bad.

You guys test the voltage by probing the tps wires whiled plugged in and key on ACC right?

yes sir. I adjusted the tps and it fluctuates to 4.0 and 3.90 now. is that normal? could the ground be bad?

I would not worry about a tenth of a volt fluctuation.

That is normal if you cant keep your hands still! !

Start using small wire alligator clips and it will stop flutuating..
But, you are fine as Billc said..

NOTE: Make sure that you RETIGHTEN the locking nut to keep the TPS WOT adjustment screw from moving.

Scotty I just tried using ECU talk (free may buy Nissa Data Scan soon though).

Is it accurate enough to use those voltages? At Idle my voltages were at 0.46 not 100% on what it was at WOT but I think it was above 4.0v.

Yep.. ECU talk will show the correct voltages. Actually, its showing the exact signal reading that the ECU interpets..

Side Note: I never perform the TPS test with the car running... I turn the key in the full on position (Xmas tree lit) without starting the car.

Also for WOT setting, I hold the throttle open with one hand & adjust the throttle stop screw slowly until the DVM reads 4.0 Exactly. Then I have someone get in the car & press the gas pedal fully to recheck the reading. You would be surprised how many times the reading is different; due to binding throttle cable or loose cable connections. The cable issues can cause problems with the throttle not closing completely & not opening completely. Bottom line: Make sure the throttle cable is solidly mounted properly & all screws/nuts are tight (no jiggling).

Sweet I will get it connected today and buy a copy of Niss Data Scan because of the log reading capabilities