Does the TPS have a range? If I adjust mine so the voltage reads anything under 0.61 volts at closed positions it will not read WOT at 100% throttle, it will only go up to 98 or 99. Is that normal?? It seems like minimum to read WOT is 4.14 volts.

 

Typically (but not always) it will add about 4.0V to the closed throttle voltage.... e.g. if you start with .50 the WOT reading will be 4.5V. And, I have seen some scanners that will not read above 99%.

Can you verify that when your foot is on the floor, the blades are horizontal/fully open? If not, is the carpet in the way? Is there any resistance in the cable?

 

Thanks for the reply fred... actually on my TPS if I adjust the voltage too low and I manually open the TB all the way from under the hood it won't read WOT not from the pedal. I thought the computer would take the reading it sees at idle and then calibrate 0-100 that way...

 

I guess there must be some sort of formula in the PCM that "assumes" there will be a 4.0V difference (I'm just guessing at that number, but it seems typical), and prorates the TP% using that assumption. If, for some reason, you only got 3.9V gain when you floored it, it would read less than 100%.

I don't think it makes too much difference. The threshold values for "WOT" (power enrichment mode) are all way below 100%..... I think that anything over 70% TP% (my 94 stock program was 66% at 2,800rpm) will kick it into PE mode. There probably isn't any difference in air flow as long as the blades are actually opening all the way.