What is the TPS?
Sitting on top of your throttle body there is a sensor
that relays to the computer the exact opening position of the throttle
butterfly. In other words, how far do you have your foot into the accelerator
pedal. In technical terms the TPS is a low-voltage potentiometer. Based
on the position of the throttle and other factors given to it, the computer
will decide how rich the fuel mixture will be at any given open throttle
Why mess with the TPS?
Well, based on the information given above it is easy
to understand how important this sensor is to your Mustang's performance.
It is important that the computer gives the correct air and fuel mixture
at the right time. If your TPS is off (or bad), the information (voltage)
that the computer gets will be inaccurate. The tuning procedures in this
article are very simple and the potential for the TPS to be off is significant,
so why not tune your car the right way and get the most out of it.
Tuning the TPS
When you tune up your Mustang (wires, plugs, timing, etc.),
the checking/adjustment (if needed) of the TPS should always be included.
You will need a Phillips screwdriver, a pin, and a voltmeter that can
read low voltages accurately. Here is the procedure:
1) Loosen the two screws holding on the TPS, (The screws
can be very stubborn, so make sure you have a good quality screw driver
that fits snug and has a long handle for lots of torque, or you might
strip the heads) just enough to able to swivel the TPS with force.
2) Pierce the "GREEN" wire with the pin and hook the positive
(+) lead from the voltmeter to it.
3) Ground the negative (-) lead from the voltmeter. Use a good ground,
like the engine or other grounded metal source.
4) Turn your ignition key to the run position, but do not start the vehicle
5) Rotate the TPS until you achieve .98 to .99 Volts (For stock or slightly
6) Tighten the screws on the TPS and recheck.
If the maximum or minimum voltage you can obtain is close
to the above recommended voltage setting (.98-.99), but the TPS just won't
turn enough to get it right, you will have to modify the TPS. If you get
a very low voltage reading, make sure you have an accurate voltmeter and
your connections are solid, if so, you need to replace your TPS. If you
have no voltage, you have a bad connection or a bad voltmeter. Rarely,
if never, will a TPS be in such bad shape, especially if your car still
See Also: Modifying The TPS
Article by: Glen Profile