could i have put my tps on wrong? i had no idea that i was suppose to mark where the groove was when i changed them. it runs pretty good so i never really thought much about it but now that i think about it i can have my foot steady in the throttle and the rpms will drop down, or i have to push my foot way down for the rpms to change any. could that be a symptom of a tps? my dads truck doesnt do it and my buddys dads truck doesnt do it and my buddys new truck (same as mine except reg cab) doesnt do it either.

could this be a tps problem or am i looking at something else? i also have a little bit of hesitation when i floor it? i read on the fullsizebronco forum that some vehicles needed the dial marked but others didnt. i dont know if mine is that kind or not.

 

The best way to figure out if the TPS is on wrong is with a meter. You could also run the KOEO and CM tests. There is an error code for the closed throttle TPS value too high.

Personally I do not much stock in the theory you need to set the TPS to .99VDC at closed throttle. Anything between 0.6VDC and 1.00VDC is good. The PCM is always looking for the lowest value, so no matter where you put it between those values the PCM will be happy.

 

If you have a v8, you need to adjust the TPS. The procedure is in the haynes and chiltons manual. You'll need a multimeter to measure the open and closed voltages and move the TPS until they're in the right range.

 

Sounds like you may have got a bad TPS. Where did you get it?
Their is no adjustment. Just check it after you install it and the voltage with the key on and CT should be about 0.9-1.0 VDC but 0.6VDC to 1.00VDC is good also.
I have no idea what you mean by some vehicles needed the dial marked. Never heard that one.

A TPS sensor has three positions, CT, PT & OT. The computer samples the voltage when you start the engine and uses that voltage as CT. That is why you should never touch the Throttle when starting the engine.

 

That's my point Andy, in real life I have found as long as the closed throttle TPS value is in the range I listed you should be good. Of course it would be prudent to verify the open throttle value is at or above 4.5VDC.

Ryan has some great info at his site to backup my viewpoint: Ford Fuel Injection » Throttle Position Sensor (TPS)

Maybe I am reading your response wrong, but most TPS sensors are non-adjustable.

 

How do you measure it with a meter? Do you do it with the engine running or just the key turned on?

 

It should measure the same with the engine running or not.
But the key has to be on.
The throttle closed (CT).
You put the meter on DCV.
You touch the the black lead to SIG RTN.
You touch the red lead to the TP wire going to the computer.
Then you touch the red lead to VREF.
You note the readings for TP and VREF.
You can also check the readings at PT and OT positions.

For more information go to the link rla2005 posted above in post #5.