lmichie wrote:Trying to recap, what I was thinking and olcoolone was suggesting, if the "system" was switched in at 0.8V and 1.6V so they are "invisible" then switch out the tps so only the "system" is supplying signal. Then manipulate the "system" to supply idle up signals eg 1.2V and 2.0V so the gap remains constant. Then reverse to go back to accelerator control. Could be done with a multi position switch and some relays. to make sure the sequence works.
You wouldn't have to use relays to switch and isolate the output from the ECU to the input of the pedal, you could just use a two pole switch....... if the reference voltage going into the pedal was 5v and only the outputs from the pedal changed with a differential of 0.8v between the two then all you would have to do is introduce a voltage on the output side of the pedal.
If you concerned about the output from the ECU being upset by introducing a voltage to the pedal output..... there is no concern unless you increase that voltage higher then the actual voltage out of the ECU.
Example...... If the output voltage from the ECU is 5v and the output voltage from the pedal was 2v and you introduce a 3v signal to the output of the pedal then the original 5v output from the ECU would still be 5v, the output of the pedal would then increase to 3v...... if instead of 3v and say you introduced a voltage 7v to the pedal output then there may be a problem.......
The TPS has nothing to do with the pedal and RPM.
What you have to do is fool the ECU into thinking the pedal is pushed down that will increase the throttle movement on the inlet and the TPS will follow feeding back information to the ECU for fuel and timing to keep it at an optimal burn rate.
The TPS just relays information...... if you increased the voltage ate the TPS you would not increase the RPM...... you will only make the engine run lean or rich.