Hey Mr.Nickleye?

[scruffboy]

In my last post you answered my question by saying that the Throtle Position Sensor is good to go out of the box. On another forum, they tell me it has to be callibrated and they point it out in the TSRM. It says to put a .58 guage between the throtle stop and lever, connect an ohm-meter to two terminals, and gradually turn sensor until the ohm-meter deflects. Some questions. Is all this necessary? What does deflect mean? Also, is an ohm-meter something a backyard mechanic needs and how much do they cost? I'd be real happy if you could find the time to answer these few questions.

Scruffboy

[IHateHacks]

I know I'm not Mr.nickleye, but I can offer some info.

First, you can buy a multi-meter which can measure ohms, volts and amps. You can get a cheap one from any parts store for about $15. Home depot sells better ones for around $50. And yes it is a necessary tool for diagnosing electrical circuits.

You are correct about adjusting the sensor. Mr.Nickleye was not wrong. Think about it, the sensor has eccentric holes, you think you can just slap it in at any spot? Here is the TSRM way of adjusting a throttle position sensor on a 7M-GE (7M-GTE's clearances are different).

Looking at the TPS terminals from top to bottom the terminals are labeled E2, IDL, VTA, Vc. Top to bottom.

Put the sensor on the throttle body and put the screws in but dont tighten them all the way.

As you stated put a .58 mm (.0228 in.) feeler gauge between the throttle stop screw and lever and connect an ohm meter to terminals IDL and E2.

Now turn the sensor clockwise until the there is infinite resistance shown on the ohm meter. Thats the jap to english conversion of deflect. They also call grounds- earth, not a good translation for the TSRM.

Now tighten the screws, and check resistances. With a .40 mm (.0157 in.) feeler between lever and screw there should be less than 2.3k ohms between IDL and E2. With a .75mm (.0295 in) feeler there should be infinite resistance between IDL and E2.

Then check the resistance with no feeler gauge between termianls VTA and E2. It should be between .3-6.3k ohms.

And with the throttle fully open resistance between terminals VTA and E2 should be 3.5-10.3k ohms.

Hope this helps.

[scruffboy]

I appreciate the help IHATEHACKS. I thought those holes were elliptical for some reason. Tell me if I understand this correctly. Infinite resistance means a closed circuit, no electricity flowing? Is that correct? I definitely am not up on my electrical knowledge, but owning a Supra I feel I need to learn, as there are so many damn sensors on the engine. Again, thanks for jumping in and answering my question, your advice is right up there with Mr.Nickleye's as far as I'm concerned (though Mr.Nickleye has helped me so many times I don't have enough fingers to keep count).

Scruffboy

[mrnickleye]

hackhater's post is very helpful. Perhaps this thread will become a sticky.

[QUOTE=scruffboy]Tell me if I understand this correctly. Infinite resistance means a closed circuit, no electricity flowing? Is that correct?

Infinite resistence is what you'll read on the ohmmeter when there is an 'open' in the circuit you are testing.

Read all about it here.

http://www.allaboutcircuits.com/vol_1/chpt_8/6.html

If you took a piece of wire and placed the red lead on one end, and the black lead on the other end, the meter will read 'some' resistance in the wire. The metal the wire is made from will slow down the flow of the electrons passing thru it.

This whole area of electicity, and current flow, and resistance can get very interesting, and complicated.

[scruffboy]

Thanks for pointing me down the road to electrical knowledge. I will put some effort into this as it seems important when working on these newer cars (listen to me, a 1989 and to me it seems new. I'm used to carburators and distributors and the like). I must be showing my age here, huh.

Scruffboy

[damdog05]

the picture in the tsrm isnt that great at showing where the throttle stop and lever are. does someone have a picture or can explain it. or maybe an exploded view of the tsrm picture. thanks for the help. i have no clue where those are.

[scruffboy]

The TSRM pics suck at showing the lever and stop. I tried taking a picture but my photogrophy skills leave a lot to be desired. I'll try to explain it, if I can. On the NA, behind the throttle body you will find the "linkage", the cable that pulls when you step on the accelerator. With your car running (and in neutral, of course), pull the linkage to rev the engine. You will see a lever pull back, and a space open between it and a small rod with a rubber boot on it. Let go of the linkage and they will come back together closing the space. Hope that helps. If anyone else would like to add to this, feel free, as I am not an expert.


Scruffboy

[IHateHacks]

The nut (with the yellow paint on it) and stud in the middle of this picture is your stop screw. The throttle lever is touching the bottom of it.

[damdog05]

it sounds like your talking about the the idle adjustment screw. is that where it needs to go? or is it somewhere near that? im about to look at my car to make sure but am i close?