Throttle body open percentage and ALDL readings

[crazybiker]

Ok, I've got an ALDL cable and programs to read some of the data that you get out of it, and when we flat stick the car, the data readout says we get about 79% throttle, but when I look at the throttle body and open the butterfly manually, it opens all the way?

1st, do I need to use the pedal to check this?
2nd, if the pedal is opening it all the way, why is the computer thinking it's only 79%?
3rd, if yes to the above question, am I losing power?
4th, if yest to the above 2 questions, how the hell do I fix it?

Thanks guys

[Cheap6]

If you are using WinALDL there is provision in the configuration window to set the 0% and 100% TPS voltages. It's not an issue as, within reason, the ECM 'learns' the TPS voltage on each start as the zero throttle position.

To check the mechanical side, have someone open the throttle fully from under the bonnet (engine off, ignition on) and set the 100% TPS voltage from that. Flatten the pedal to the floor and check that the TPS again reads 100%. If it reads less than 100%with that, adjust your throttle cable to fix it.

You can also adjust (or at least check) if the throttle is truly opening fully when against the stop on the throttle body and there is a 'How To' on that.