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Adjusting TPS on an Automatic using LastHumansGarage technique

2715 Views 5 Replies 2 Participants Last post by  monkbonk
I'm not that good at playing chopsticks with my multimeter probes. When I was tuning the TPS sensor (rotating it), I could get to about 0.06 Ohms.

Lost the position where it was reading decent resistance, so I've opted at going with LastHumansGarage's visual method. The only difference between his TPS and mine... is that he was adjusting a manual trans TPS that had only one "points looking sensor."

Do I just adjust mine, same as his, and not worry about the bottom one? Or should I replace the TPS with a new one?

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The lower armature is for full throttle. So, in essence, I'd just want that portion to make contact when the car's throttle is fully open (gas pedal depressed). I can still use LastHuman's method just as long as I take into account the full throttle positioning too.

Found this youtube comment by nismoz31turbo:
not sure bro, but I think the microswitch makes contact at idle, on the manual z31 that is all that is used..on the auto z31 there is another switch in it that goes to the tranny and tells it to kickdown at full throttle, that is actually a throttle valve switch, a tps uses a rheostat that varies the voltage going through it depending on the ohm restistence, like a lightswitch you turn..I have learned alot from your videos thanks for posting, and you are giving me new life to fix my z31 turbo :)

My tps may have been moved at some point, as it was already at an odd angle. I think.
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Adjust the idle switch as per FSM, the rest will take care of itself if the TPS is working correctly.

To make adjusting the idle switch easier for myself, I use a modified set of multimeter leads that have little spade connectors on the ends. I set the meter for audible continuity warning so I can hear when the idle switch is closed. Job done.

The "WOT" switch in the TPS is not a kickdown switch. You can test for yourself that the WOT switch closes well before actual WOT.
The kickdown switch is in the cabin and operated by the throttle pedal. Some people don't read the FSM for their car and make up stories instead, but don't mention that their stories are conjecture.
Did the adjustment with the multimeter. I also just replaced my CHTS.

Now, my car will do fine in Drive or Reverse where previously it had coughed/stalled and stopped running. The issue now is that it cannot hold an idle (park, neutral and drive gears).

I'm going to recheck my timing/codes.

EDiT: Will idle with AFM unplugged @ 1000RPM.
Codes I received: CAS (haven't checked timing again yet, need to check electrical harness again?); Fuel temp, AFM, Load Sensor Code 31.
MAF or wiring is suspect if it idles adequately with the MAF disconnected. Did you get the MAF code before you unplugged it?
A repeating CAS code is a worry.
If you cannot make the Code 31 go away by operating the AC, heated rear window or headlights, then the related wiring is suspect.
I received the MAF code before I unplugged it, yes.

When doing the FSM tests, the MAF wiring failed (the one where you use the three lead jumper wire on the connector/measure 0 ohms resistance) and the MAF itself failed when I applied battery voltage to terminals D and E while measuring from B and D (got 12.11 volts instead of 1.##).

I don't believe my MAF harness is suspect. I couldn't find anything visual that would indicate it needing replacement.

I tested a 1987 Maxima MAF on the car. The idle was low, but it ran noticeably different. I think the smaller diameter sizing of the Maxima MAF limits airflow.

I eliminated the CAS code. Someone did not tighted the dizzy screw appropriately.

I soldered the fuel temp wire onto the fuel temp sensor, but I'm still getting code 41.
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