Hey folks. So, I might just be retarted, but I am having a slight problem with a home-made TPS adjustment tool.

I built it just the way all the threads here say to: two 12V LED's and some spade terminals.

When plugged in, trying to set the TPS, only 1 light will light up when the throttle is opened rapidly, and then goes dark with engine deceleration.
No amount of adjustment will get it to leave either of the LED's illuminated at idle.

Has anyone encountered this issue before?

A new TPS is on the way... let's hope that'll magically make it behave correctly.

 

Well the light adjustment is pretty rudimentary. I would recommend using a digital multi meter and setting it with volts. 1Vdc with the engine fully warm.

 

you adjust it with the engine fully warm and OFF, but with the key to on.

sometimes it takes a while to get both the lights to come on. then slowly turn until only one light is on

 

The whole test light method is stupid as hell when multimeters can be bought for like 5 bucks and used for many other things, like the electrical problems our cars are notorious for having.

 

Setting by volts is not as acuurate as using 2 MM, or the test light back to the ecu. Over the 20 years of ownership with the S5TII, been there and when using any other method, then the factory recommended method, the performance is compromised.

 

I set the TPS by volts and I measure whether it's still working right by checking resistance

 

I just set the TPS using the light method and quickly followed that up with a voltage reading check and it read 1.024 v.

 

make sure the engine is WARMED UP and OFF with the key to ON!!!! if you dont then sometimes both stay off. sometimes i have to turn it off then back to on a few times before it does it! good luck man!

 

It's much easier to it when the engine is cold, naturally with the key on, but use a screwdriver to keep the fast idle cam out from under the linkage. Thiis way you can take your time and no hot engine to work over.

 

When setting the TPS, if I open and close the throttle and let it come to a rest, I get one reading. Putting a little bit of force in the closing direction changes the reading a fair bit; going by resistance measurement across the "narrow range" pin, it drops from 1kOhm to 0.883 kOhm.

Do I need to clean out my throttle body? Or is that offset effect to be expected?

 

may just need to adjust the TPS mount screws

 

Certainly it's going to change if you put pressure on the linkage when the throttle plates are closed, or let's say at idle position. As long as the linkage returns to the same postion and the TPS reading is the same let it be.