Throttle Position Sensor

[FL318is]

Can anyone point me to a link regarding the TPS function and cost?  I have looked on http://www.realoem.com but must not be looking in the right category.
My car does not have one connected.  When the old one is connected the car idle rpm goes up and down.

[e9nine]

Interesting. My car drove like crap and triggered the check engine light when I had some issues with the TPS which turned out to be a break in the wire.

http://realoem.com/bmw/diagrams/g/v/10.png shows the pic

Navigate to: FUEL PREPARATION SYSTEM  => FUEL INJECTION SYSTEM

[FL318is]

I found that earlier but the cable that connects to the Thottle valve switch is what I am wondering about.  If the TSP goes bad would that be the Thottle valve switch or the cable?  

I also have an additional cable spliced in to the MAF.  Under the rubber boot of this additional cable is some sort of relay looking box, looks like something that should be with a DME chip. Having fun now.

I'll take some pics.

Thanks again!

[e9nine]

Good news is our TPS can be tested as it's a potentiometer.

When you wiggle the cable, does your idle change any? Have you tried cleaning the TPS with some brake kleen?

Pics would help to see the box you're describing as I am drawing a blank. We have a AFM not a MAF as well

[bmwman91]

Is there a sort of extension cable thingy on your AFM that seems to serve no purpose, and there is a little black box thingy that the 5 wires pass through?  I had one on the car when I bought it, and since mangled it while using it to take readings for the MAF conversion.  I am pretty sure it is just a noise/feedback eliminator.

[FL318is]

Is there a sort of extension cable thingy on your AFM that seems to serve no purpose, and there is a little black box thingy that the 5 wires pass through?  I had one on the car when I bought it, and since mangled it while using it to take readings for the MAF conversion.  I am pretty sure it is just a noise/feedback eliminator.

That sounds just like it.  So remove it?

[FL318is]

Good news is our TPS can be tested as it's a potentiometer.

When you wiggle the cable, does your idle change any? Have you tried cleaning the TPS with some brake kleen?

Pics would help to see the box you're describing as I am drawing a blank. We have a AFM not a MAF as well

With nothing connected to the TPS http://www.realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=13_0309&hg=13&fg=15

(ie, you can see the male prongs, #2) the idle is smooth.

 But, when you connect the cable end to it, raise the RPMs and hold the RPM, the smooth idle now goes up and down, almost as if you touched the gas pedal and lifted your foot off and repeated it.  I will try cleaning it.

Thanks for the AFM not MAF.  I can wax but I don't do well with tools and parts.  BUT, I will be learning.

[cutncheese]

Is there a sort of extension cable thingy on your AFM that seems to serve no purpose....

A little off topic but... I just got finished fixing a problem with my car, I had it into the dealership twice and they couldn't figure it out. After some experimenting it turns out there was an issue with that extension cable I took it off and plugged the wire in directly and it worked!