VDC, between 1-5 volts
this is for a 5.0 but should give you a good idea what you are doing
How To Adjust TPS
"Muscle Mustangs & Fast Fords"
April 1993
The throttle position sensor is one of those things that falls into the category of "computer stuff" that makes a big difference and is easy to deal with, but average people like us would never know about. Without the proper adjustment, the throttle position sensor (TPS) will give the computer a false reading as to the exact throttle opening. A false reading will limit wide open throttle performance (something we definitely don't want). A voltage reading must be taken using a digital volt/ohmmeter (DVOM) with the Key On/Engine Off and with the Key On/Engine Running. A Radio Shack DVOM, part No. 22-185A, works well for this job.
The TPS is located directly on top of the throttle body and is adjusted by loosening the two phillips mounting screws and swiveling the sensor until the highest reading is found. It may be necessary to elongate the holes with a small file to achieve the desired reading.
The spec range for Key On is from .88 to 1.0 volt; shoot for the .97 to .99 volt. With the engine running, the voltage should be no higher than 1.05 volts.
Incorrect Throttle Position Sensor (TPS) voltage will result in reduced performance. The best way to take a TPS voltage reading is by using two safety pins through the wires coming from the sensor. The positive lead is attached to the green wire, while the negative goes to the black wire. Always ground the meter through the sensor's black wire. This gives a direct, and more accurate ground into the computer
