Thread: possible to have good tps volts but bad tps?

i was wondering if anyone had ran into a bad TPS but got good volts? my volts dont read bad i get over 4v at WOT, but my idle is rough and when i unplugg my tps it doesnt really effect my idle too much, the car doesnt ie or anything like that, also when i start my car i get 2000rpm idle, then down to 1500rpm then 2000rpm...i normally see around 1500rpm idle anyway becuase of a stupid aac problem, but was getting stumped becuase the idle i rough and i have look at everything else but cant figure it out?

I had the same exact question, still not quite sure, myself.

Calum told me that as long as the voltages are correct, that it should work fine.

All I know is that I switched my TPS out for a new one, and nothing changed one bit.

the thing i read is measuring the voltages with a multimeter doesnt work beucase it has a buffer so the volts dont fluctuate, but if you use a analog multimeter they work better becuase the needle will move and twitch...

i donno

I look at the gauge or voltage in nissan datascan or calumsult, respectively.

Yes I have... Here's how you verify that the TPS is good after good volt reading:

Perform a TPS Ohm Test:

Test resistance between Terminals A & B (Same terminals used for Volt tests; just change the DVM to Ohm's)

- Completely released (Closed Throttle): Approx 2 ohm
- Partially released (Gradually Opening the throttle): 2 - 11 ohm
- Completely depressed (WOT): Approx 11 ohm

If not, the TPS is bad.

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Your problem of a jumping/hunting idle is usually Dizzy or Aux Air related.

Dizzy Check
- Open your dizzy and check for the presence of oil inside. If found, dizzy shaft seal worn; swap in another dizzy.
- Check the rotor for wear on the tip
- Check the cap for contact post wear or cracks.
- Clean each plug wires with mild detergent & shop towel. Make sure all wires are completely plugged back in.
. Then, start the car. While using a household spray mister, lightly mist water across the wires starting at the dizzy moving to cylinder 1.
. If you see any little sparks jumping between wires, Replace the wire set.

Note: If you replace any of the above parts, put in timing mode, then reset your idle first & then reset your timing.

AAC Check (Round unit on the IACV)
- Disconnect AAC valve harness connector.
- Check AAC valve resistance across terminals: Resistance should be approximately 10 ohms.
- Clean the IACV unit with Throttle body cleaner.

Air Regulator Check (located on passenger side under intake mani; accessable only from under car)
- Disconnect Air Regulator harness connector.
- Check Air Regulator resistance across terminals: Resistance should be approximately 70-80 ohms.
- Remove Regulator and check for clogging & good operation (opens & completely closes).

MAF ground check
Check that your MAF ground is good.
- Connect the DVM Positive lead to the middle wire on the MAF. (use a paper clip wedged in there)
- Connect the DVM Ground lead to one of the ground screws on the rear of the intake mani
- The Voltage read should be less than 9mv (.009v), if it is above this value, the sensor needs to be regrounded to the Intake Mani grounding screw.

Lastly after all of the above, your car is still hunting: Check/Change all of your vacuum lines. If you have EGR stuff still installed, that would be the next area to test (EGR valve, EGR solenoid, EGR pipe clogged, all of the EGR hoses, BPT valve and the AIV).

Fixing the hunting idle is not easy as it can be caused by many things.
But I found that one of the above items usually is the culprit.

Good Luck..

^^^ I don't even wanna try that hard lol. You pretty much summed it up haha.

well when i nplug my aac valve nothing happens with the screw all the way in , nothing happens idle doesnt drop below 1500 rpms that might be it

Me either... but thats what it takes to zero in on the source..
This is just a bunch of DVM testing. Its like 5-10 minutes each.
You of all people here, know its easy to validate the condition of these sensors..
Just hard to identify the problem unit!



Were you in timing mode? Turning the screw without the car in timing mode will not change the idle. You must test the AAC with the DVM & adjust the idle in Timing Mode before determining that the AAC is not functioning.

What is your timing set at?

If you validate the condition of each item in the order listed, you will probably find your problem. My bet is on the dizzy causing your problem, based on the info provided.

Btw: Check your sensor grounds located on the rear of the Intake mani. Make sure that all 5 or 6 grounding wires are connected to the 2 grounding bolts (making sure none of the wires has broken off or frayed). Loosen both grounding bolts a few turns and simply retighten them.

Whats this jazz i see people writing about them adjusting their TPS... (in reference to voltage)

I tested my TPS for resistance like you said, and i got 1k closed and 10k WOT... Do i adjust it? or replace it?

double post