CarrieB

I have an 89 5.0L Mustang, what should I have the TPS voltage set at?

7upedition

0.98-0.99 volts from the green with to ground with the key in the accesory position, not on though.

Joel5.0

Ford TPS sensors are not adjustable......anything between .8 - 1.0 vdc is optimum, and anything between .6 - 1.1 vdc is "acceptable".....the computer will take care of the rest.....adjusting the TPS to .9999 is a MYTH......... BTW....having the key in ACC doesn't power up the computer to generate the 5vdc Voltage REFerence for the sensors.

7upedition

i was able to adjust mine around to make a difference in the voltage reading... and per procedure the key is not to be in the on posistion, just the accesory (forward but no start).... unless it's lying to me? [&:]

yellow93lx

Look under the "!!! TECH ARTICLES !!!" at the top of the forum and there is a thread on how to set it.

7upedition

Throttle Position Sensor
"The throttle position sensor is housed on top of the throttle body. This rotary-potentiometer-based device sends a voltage signal to EEC to indicate the position (and rate of change of position) of the throttle shaft. Ford service literature shows that a five-oh's throttle position sensor's signals range between .6 and 4.585 volts, the lower number indicates that the throttle is closed and the higher signaling wide-open throttle. With the engine off and the ignition key switched on, a digital voltmeter connected across the sensor's wires should read .85-1 volt. At idle, a reading of .98-1 volt is considered desirable for performance service. A TPS setting of 1 volt at idle produces 4.6-4.8 volts at wide-open throttle.

Adjustment involves loosening the pair of screws that attach the sensor to the throttle housing and rotating the sensor until the meter reading is corrected. The meter's positive lead connects to the sensor's green wire and the negative lead goes to the black wire. Due to variations in production equipment, the holes in the sensor housing may require elongation before it becomes possible to obtain the desired reading. For reference, the 1994-1995 TPS uses different-colored wires, and the hold-down holes in the sensor housing are not accessible as on previous models. In July 1989, Ford issued a Technical Service Bulletin covering hard-to-remove throttle position sensor mounting screws."

Courtesy of Al Kirschenbaum
The Official Ford Mustang 5.0 Technical Reference & Performance Handbook

jasonvri

7up-
quote that book all you want...

Some of us have actually read the GUFB, and it does not matter what the tps is set to.
The ecu sets its own baseline, which it calls 'idle'
From that 'idle' setting, the ecu adds ~2.7v (IIRC) to determine WOT.
That is the only absolute use of tps voltage.

All other uses of the tps involve the rate of change, rotary acceleration of the tps signal. In other words, how fast the throttle is being pressed.

Any setting that does not trigger a CEL will run just as well...
Joel already stated the proper range...
Setting to .9999999v is a waste of time...

The magazines beat the .98-.99v myth into our heads for so many years... It is sad really,

jason

samseed101

+1. I see it every time I start the car to do some datalogging. I can monitor the loop state, TPS voltage, etc. For awhile, I had the OL / WOT breakpoint set to 3.0 meaning that at 3.0v above baseline it would force into WOT and OL status. I had it set so high because I wanted to log as much as possible in CL to really help dial in my MAF transfer curve. But once that was done, it went back down to 2.5, which was actually 2.5v above baseline.

Of course, I have an SN95 so setting the voltage is useless anyway.

jasonvri

I said something misleading...

I haven't actually read ALL 5-600 pages yet... I keep falling asleep...


jason

Joel5.0

Go to http://www.veryuseful.com/mustang/te...g-TPS-FAQ.html instead.....Al Kirschenbaum, although he did a GREAT JOB with the book (I also have it),.....has added to that myth......all the OEM Ford literature, TSB's and specifications regarding the TPS...have something in common....."NOTE: The TPS is NOT ADJUSTABLE".....

OK....don't take our word, would the latest version of a tech manual, or FoMoCo's (Ford Motor Company) S/W Engineers that designed the EEC-IV logic do?......



Would this data prove the point?.....