How To Adjust TPS
"Muscle Mustangs & Fast Fords"
April 1993
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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.