Need help understanding something in the TSRM (TPS adjustment)

[scotty]

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=103

4 c, where it says "gradually turn the sensor clockwise until the ohmmeter indicator deflects, and secure the sensor with two screws".

What does the "deflects" mean? I've got the ohmmeter on so that it makes a sound when there's continuity. At the beginning there is continuity, then I turn the sensor gradually, so it starts to read some values, and then it goes to unlimited ohm. Where am I supposed to stop the sensor?

I've tried both doing it when it just starts to read a value, but get the wrong numbers when checking the TPS terminals.. so then I tried to stop the sensor just before it reaches unlimited ohm, but still get the wrong numbers..

 

[Nick M]

It means the analog meter needle jumps.

 

[scotty]

It's a digital ohmmeter..

 

[ben1984j]

What does the "deflects" mean? I've got the ohmmeter on so that it makes a sound when there's continuity. At the beginning there is continuity, then I turn the sensor gradually, so it starts to read some values, and then it goes to unlimited ohm. Where am I supposed to stop the sensor?

The point at which the ohmmeter "deflects" is where it goes from a reading of resistance to a reading of no continuity (infinite resistance).

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=103I've tried both doing it when it just starts to read a value, but get the wrong numbers when checking the TPS terminals.. so then I tried to stop the sensor just before it reaches unlimited ohm, but still get the wrong numbers..

Sounds like you did it right the second time...what numbers were you getting with this method?

 

[scotty]

TPS adjusted as close to infinite resistance as possible with 0.70mm, between IDL-E2 terminals.

Here are my readings:

I know that the two last values are not correct.. but what can I do about that? I've one more TPS from my GE engine(same part number), which I've tried, I get about the same values on that aswell.

 

[ben1984j]

You're mostly just concerned with the IDL-E2 readings (and yours are fine). I couldn't tell you all the technical specifics, but I know that the ECU only uses VTA for transient throttle events...it has little impact on overall drivability.

 

[Nick M]

It's a digital ohmmeter..

Then you need to watch the digial screen. Deflection is the needle movement all the way across in one sudden motion.

 

[gottadiesel]

I used a fluke 87 digital meter myself and I just set it with sounder on for continuity, so I just adjusted until the sounder went off... (you are just measuring across a N/C switch, that opens when throttle opens) although I had problems with using feeler gauge, so adjusted it my sight and once tightened made sure the IDL-E2 contact changed state with just every so slight movement of the throttle, my understanding is that it's (it being IDL-E2 contact in TPS) purpose is to tell the ECU that I am no longer idling. When I first adjusted mine I had major issues with the throttle at about 3% open, the rpm would cycle drastically, I re-set the TPS by hand and sight and all works good now...

 

[nuggets]

Scotty, I'm right there with you. I can't seem to get my TPS to pass every test (see attached photo). But here's a question that I have. What does the "-" mean in the last test (VC-E2). Does that mean throttle valve fully open?

 

[ben1984j]

Scotty, I'm right there with you. I can't seem to get my TPS to pass every test (see attached photo). But here's a question that I have. What does the "-" mean in the last test (VC-E2). Does that mean throttle valve fully open?

It means throttle position doesn't matter - VC and E2 are at either end of the potentiometer (variable resistor) inside the TPS...so the resistance between them will be the same at any throttle position.

 

[nuggets]

Thanks ben1984j! So if I'm getting no continuity (0L) then my TPS is probably bad, correct?

 

[jetjock]

That or, assuming you're on the right pins, the meter is ranged too low...

 

[nuggets]

The meter ranged too low is what it was. My Fluke had two kOhm settings and I used the one that was too low. I put it on Auto range and everything checked out ok. Phew.