Adjusting the TPS
 

Could someone explain kind of the...method of adjusting the TPS? I read the how-to many times and I don't understand what exactly you move. Do you move the entire sensor? Is it the swinging of the sensor itself that does the adjustment? I'm confused on this matter.

Thanks in advance.

Unplug it, stick a sewing needle or something into where the white wire goes into the plug, plug it back it. Turn the ignition to "on," take a multimeter and touch the + lead to that needle and the - lead to the chassis. Swivel the tps around until it reads 5.1 - 5.2 volts. (should read 5.0 but with the slight increase your idle won't be so low)

The how too instruction is of my making and the paragraph involved was taken exactly from the Subaru manual. If and when I can access the text I will add the words ---- (by rotating the complete assembly).

Meantime the existing data would appear OK, as instructions regarding loosening and tightening the fixing screws, should provide an adequate clue.

I guess. I think a picture would help too. I'll take a picture or two tomorrow while I'm adjusting my sensor so maybe that can be added in.

you are rotating the whole sensor, just loosen the two screws holding it to the throttle body and it will rotate somewhat smoothley by hand. you want to stick a pin or needle through the middle wire of the tps then hook your meter up to it and a ground source. for connecting the meter I reccomend the wire with alligator clips on both ends as they leave your hands free to hold the meter while rotating the tps.
hope this helps let me know if i need to clarify parts of it

My instructions, as is included in the how too:-

"ADJUSTING AND CLEANING THE THROTTLE POSITION SENSOR.

In order to adjust the TPS, the manual says to measure voltage at the TPS by inserting meter probes into the plug at the ECU. Nice and easy that is! In order to accomplish the feat without tying yourself in a knot you will require, best of all, one of those dress making pins with a nice thin shank and a knob on the end, or a thin needle. Also a meter to measure 0.5 volts D.C..

The TPS comprises a potentiometer, presumably used in a voltage divider configuration, as three wires come from it. There is a plug and socket close to the unit so that it can be easily removed for servicing. At this plug, the wires are --- black ground and one end of the resistance element, red the other end and white the wiping contact.

Stick your pin right through the white insulated wire so that you can clip your meter lead onto it to make measurements. A fine pin will not damage the conductors as they will spread and there will be no significant damage to the insulation. Measure between the wiper, i.e. white wire and ground, by connecting to engine, chassis, battery negative, or whatever.

Now from the book: (i.e. Taken exactly ftom the Subaru Manjuals.)

1. Connect all connectors.
2. Loosen TPS fixing screws.
3. Turn ignition on.
4. Adjust TPS position while throttle valve is FULLY closed, using a volt meter, to the specified voltage.
5. Tighten fixing screws.

The voltage is specified within a tolerance from 0.45 to 0.55 volts. You should have no trouble in setting things at exactly half a volt. (0.50)

Before removing the TPS or altering the original setting, it is a good idea to mark the mating castings with a scratch so that one can check on the adjustment, before and after, as a matter of interest. It is always nice to know if the effort expended has in fact improved things."


Surely when read completely through, the procedure is easily fully understood. :confused:

However text as per the manuals (4), could be altered as follows, if someone able to do so has the inclination.

4. With throttle valve is FULLY closed, using a volt meter, adjust the position of the TPS by rotating the complete assembly in relation to the mounting, until the specified voltage is registered. Note that slotted holes are provided in the assembly to allow for this adjustment.

fixed the decimal placement...

I had a quick look at it Trevor. The document that is on there is a pdf, and like 99.99% of the b'stards, they don't allow editing.

I'm sure we can get it altered though, or replace it with a new version.

Joe;):D

Just a note guys.

I've always adjusted the TPS to 0.50 untill Mike/LAN told me that we get a smoother idle at 0.48.:o:)

And the higher # value that you adjust it to has a tendency to more fully engage the AWD where applicable.

That means if you set it too high you could have more AWD engagement at lower speeds than you should.

Another thing, when using the SSM and adjusting the TPS, USUALLY,
(as in almost always) when you set the TPS to a value, like to 0.48 in the engine mode, when you check it in the transmission mode it reads 0.02 higher!

So when set at 0.48 in the engine mode, and checked in transmission mode it then reads 0.50!

That's pretty interesting information Tom, thanks.

Joe

I'll see what I can do to it with Acrobat...

Trevor, I don't doubt your ability to write the instructions, however I being...well..stupid sometimes didn't understand exactly what to adjust. I still think that a picture with an arrow will clarify (for other people like me who just don't get it).

I think it's my inclination that to adjust things, I usually need to take them apart. This adjustment requires virtually no disassembly.

Exactly what do you mean by engine/transmission modes?

Hi Trevor.:)

When you hook up a Subaru Select Moniter you have four modes to check out your SVX.
The first that pops up is EGI, to check the engine parameters
then AT for information on the automatic transmission,
AC for checking out the air conditioning stuff,
and CC for the cruise control.

On the engine mode you can check the vehicle speed in both MPH or KPH.

But in the trans mode you can check either speed sensor #1, or #2,
in both MPH and KPH.

In EGI and AT you can check engine temp, in both farenheit and celsius,
and THOSE readings show the same...

More later.:)

Seems like SOMEONE is having fun playing with his toy...:rolleyes:

He's rubbing it in Craig, just 'cos the rest of us don't have one!!;):D