throttle positioning sensor?

As Noobz stated above, check the codes, I believe codes 23 and 63 are TPS related.

To set the TPS, find the sensor on top of the throttle body. Get two straight pins. Stick one into the black wire and one into the green wire so you can get the reading off them. Using a digital voltmeter, put your black test lead on the pin for the black wire for ground, and the red test lead on the green wire. With the key in the run position but with the engine not running, you should have .5 to 1 volts. Anywhere within that range should be ok. If you do not have the voltage in that range, loosen the screws on top just enough to turn the sensor with some force. Clockwise will raise the voltage, counter clockwise will lower it. Try to get it within the above range, then tighten the screws, then check again to make sure it didn't change. Then, have someone help you by pushing the accelerator to WOT while you are measuring the voltage to verify that voltage is increasing by at least 2.71 volts.

In some cases, like mine, it still won't work. Luckily I just replaced mine today with a spare I had from another throttle body. I set it with my voltmeter and my drive to work went without any trouble. Good luck, let us know when you find the problem.

Dumping the computer diagnostic codes on 86-95 Mustangs

Revised 26-July-2011. Added need to make sure the clutch is pressed when dumping codes.

Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

Post the codes you get and I will post 86-93 model 5.0 Mustang specific code definitions and fixes. I do not have a complete listing for 94-95 model 5.0 Mustangs at this time.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. On a manual transmission car, be sure to press the clutch to the floor.
Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.





If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems. This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and driveablity problems

Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off, and clutch (if present) is pressed to the floor, and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see Equus - Digital Ford Code Reader (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.
Or for a nicer scanner see http://www.midwayautosupply.com/p-7208-equus-digital-ford-code-reader-3145.aspx– It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.