TPS Gauge for better economy?

[whiskey_juliet]

The vacuum gauge isn't a reliable source for judging throttle position. It would vary based on RPM, load and throttle position.

I agree that tapping into the TPS gauge isn't a plausible method either due to any discrepancies the ECU might read.

Most likely a stand alone system will be used. Using a potentiometer to tell throttle position and an LED bar or digital display to give a real time readout.

[user removed]

Since lean burn is MAP related and controlled then a vacuum gauge would be the best method of maintaining lean burn. MAP can be all over the range at any fixed throttle postion, but load is always directly related to MAP or inversly manifold vacuum.

regards
Mech

[msc]

Originally Posted by whiskey_juliet

The vacuum gauge isn't a reliable source for judging throttle position.

True but the question was what is the advantage of knowing the exact throttle position over knowing manifold vacuum? How would you use a TPS readout to improve MPG?

Sounds to me like you have developed a bad habit of lifting your foot to figure out a basically useless piece of information and now your trying to break the bad habit by building an instrument to show you the same basically useless piece of information.

I could be overlooking something obvious but I don't see any advantage to having a TPS readout for improving fuel economy. Rather then making a elaborate system to show you the throttle position I think you would improve MPG more by focusing on monitoring and using more useful information.

For what it's worth it should be no problem to pick up the TPS signal. You would want to pick up the signal at the ECU, use shielded cable, and feed the signal into a high impedance amp or buffer. An Op-amp used as a buffer or an instrumentation amp would work fine. For the most accurate measurement you would pick up the signal and the sensors ground reference then feed that to a differential instrumentation amp using shielded twisted pair wire.

Mike