If you haven't already read how to do it a million times in all of the Mustang magazines then this is your chance. Here's how to check and adjust your TPS voltage. You may be asking, "What is a TPS"? Simply put its a Throttle Position Sensor. The TPS is a sensor that tells the ECM (computer) how much gas you are giving it, which in turn lets the computer decide how much fuel and spark to give you.
The TPS (green arrow) basically bolts to the throttle body with two screws. (blue arrows) The holes that the screws go through on the TPS are elongated so you can twist the TPS in either direction to adjust it. To adjust the TPS all you have to do is loosen (don't take them out) both screws and move the TPS until you see the right voltage.
To check and adjust the TPS you'll need a digital multimeter, two small straight pins, and a screw driver.
To hook the multimeter up you will have to pierce the green wire (red arrows) with a pin so you can check how much voltage is going through it. The red or positive (+) wire on your multimeter will go to the pin in the green wire.
Then you'll have to either pierce the black wire (red arrows) and put the negative wire from the multimeter to it, or just put the black multimeter wire to a good engine ground.
Now to check the voltage. Turn on your multimeter and make sure all of the wires are hooked up right. Then turn the ignition key to the on position, but don't start the car. You should be getting be getting a reading on your multimeter. It should be .98-.99 volts. If its not, then its time to loosen the screws on the TPS and move it around until you get it right. When its at the right voltage tighten the screws and re-check it.
If you aren't too happy about piercing your TPS wires with pins then you could do what some Mustangers do. I've seen a few guys/gals buy a fuse holder and attach the two wires from the fuse holder to the green and black wires on the TPS. Then they use the fuse holder holes to check their TPS voltage.....Whatever you do, make sure you never put a fuse in that fuse holder.
So what are you waiting for? Go check your TPS voltage.