How to test throttle position sensor
 

This test was done on a 1990 F150, but this test is very basic and will work on any year any make, any model with a TPS. Symptoms of a bad TPS is stumble or stall, always right about the same place on the throttle.

Click on the image below to start the video.
http://i863.photobucket.com/albums/a...h_M4H04325.jpg

This here is a graphical display of the signal you want. This is on my oscilloscope.
Attachment 1523