Reading through the service manual and I am not quite clear on the location of the items they are talking about. For example, the throttle sensor. This is not the throttle position sensor, correct? If that is true, where is it? And on the passenger side under the hood there is a part just under the pressure sensor, what is that? If the manual was a bit clearer with better pictures I probably wouldn't have to ask these questions.

 

Throttle Position Sensor

http://img.photobucket.com/albums/v2...425_203100.jpg

 

So what's the difference between the throttle position sensor and the throttle sensor? Are they one and the same? Why does the manual use 2 different terms?

 

Same thing.

 

The way I have adjusted the idle on the NA s4 Series is on the intake manifold there is a black rubber/plastic boot on top, remove it and there is a small screw... I think a flat head screw driver should work.. Then while its running just turn it to where you need it to be.

 

You forgot one key step: jump the initial set coupler. Jumpering this connection tells the ECU that you are about to make adjustments to the car and to NOT try and compensate. So the ECU will lock timing and cease using the BAC to regulate the idle. Then make your timing and idle adjustment (stock idle speed is 750 RPM +-50) and unjump the connector.

 

i agree

 

thnx for advice

 

Thanks for the info. What had me confused was in the service manual, page 4a-50, it mentions a "throttle sensor" and to use a "checker lamp". I have no idea where this checker lamp plugs into and what it is indicating. Anyone have an idea what they are talking about? It shows it plugged into something around the airbox. That brings me to another question. Right above the airbox, mounted on the shocktower is a device. It is right next to the pressure sensor. It has a 2 wire plug connected to it, colors R/Y & B/G. It looks like there should be a vacuum hose connected to the bottom of it, but there is not. Should there be and where does it go? Thanks again for all the help.

 

Are you sure the wires aren't R/Y and Black/Blue? If it's a rectangular little black box then that is a vacuum switch for automatics. If your car was previously an auto but changed to a manual transmission then the sensor and its associated wiring is irrelevant.

Secondly, you needn't worry about the checker light being connected to set the TPS. It's rather simple, the TPS has three wires. One of them if a funky Green wire w/Red stripe. W/key to on and the engine as hot as it can possibly get (usually requires about 30 minutes of driving time) the G/R wire should read 1 volt DC. If it is not then you turn the adjustment screw that I supplied a pic of till it reads 1 volt.

 

They very well could be R/Y B/L. Hard to tell after so many years.

Yes, this car was an automatic. There is quite a history and full disclosure would have taken several pages of explanation and hours of typing. It is actually my son's car and we converted it to a manual. Originally, another "mechanic" (and I use that term very loosely) had tried to install the manual. He did more damage than good. We have had to repair almost everything he did and chase down lost bolts, nuts and connectors. If I ever see him....well, that's another story. Anyway, thanks for the TPS info. If I understand correctly the TPS adjustment is done with the car NOT running but the key in the on position, correct?

As far as the device mounted on the shocktower, I am including a picture.



It is the round thing to the left of the rectangular pressure sensor.

 

^ That's the vacuum switch for auto's so you need not worry (and I meant to say circular but had the pressure sensor in my head when typing). You can check the G/R wire w/the car running but most would say it's an added risk. If you have just the key to on, engine not running then you need to check the voltage immediately after turning the engine off because the fast idle cam mechanism will interfere w/the correct reading being taken as the engine begins to cool off and it affects the throttle position and thus the TPS.

 

Gotcha, thanks. Adjusted to 1vdc and now it will idle and not die. It does have a miss that I can't seem to isolate. Very random making for a bit of a rough idle.

 

No matter what a someone says when I get a car,I always do a tune up on it.
All new stuff.plugs,wires,fuel filters,etc,regardless of condition,That way I know that it is GOOD.After that I can go nuts and source out any problems.
It's best to start with basics,and one of them is Compression test too,just for Piece of mind.
May not apply in your case,but I am just tossing it out there.Buddy had a misfire that turned out to be a bad coolant seal.