TPS Adjustment

The TPS, or 'throttle position sensor' tells the engine control computer the position of how much your mashing down on the accelerator pedal. It takes a 5 volt DC voltage sourced from the ECM and varies it between 0.54Vdc at idle to about 4.85Vdc at wide open throttle (your mashing on the pedal to get onto the highway or trying to show a 'stang a wonderous view of your ass). The setting of this sensor is critical as it tells the computer how wide to open the fuel injectors at all RPM and engine loads. At 4.85Vdc, the injectors are just open on a constant spray of fuel. At 0.54Vdc, the injectors are just 'piddling' fuel into the motor. Anyway, the DC voltage from the sensor is sent to the engine
control module (ECM) which is turned into a digital signal, I think, varying between 0-255 Hexidecimal, via a Analog to Digital Converter (ADC) inside the module.

Any time work is done or the base idle speed is changed, the TPS sensor has to be (or at least should be, I think) reset to factory specs. It's very easy to do as it doesn't even require the engine to be running; just a bit of knowledge in tool usage and being careful not to short anything out. Its definately for the more adventurous hobbyist and I don't recommend it for everybody. Making the extender wires is no big deal, but, to measure the voltage requires a decent DVM (digital volt meter) for maximum accuracy.