can i use one of these TPS
 

both were pulled off older (e30ish) BMWs both have only 3 wires. and if i can use them, how? i know one wire will be ground. whould the other 2 just be the 5v and signal from MS? is the 5v actually a power source for a TPS or is it a 5v from the TPS to MS?

http://img507.imageshack.us/img507/4011/img0546dx3.jpg

A variable TPS is just a potentiometer. One line is ground, one is +5v from the MS, one is the "sweep" which sends the TPS value back to the MS. You can figure out which wire is which fairly easily using a digital multi-meter.

-Mike

Those look like switch-type TPS. The BMW sensor that has been used successfully in the past is a 6-wire potentiometer-type TPS. It came on automatics, and is a round plug.

i will try the junkyard again for the 6 wire unit. the big one was just a switch type. the small one works, but it works backwards.

Then reverse the relative positions of GND and Vref. Potentiometers don't have a defined "backwards" and "forwards"- it's all up to how you connect 'em.