Hi all.

Also, while using my BASX adapter, it showed when I floored it that the throttle was only at 75%. Is this right? Shouldn't it be 100%? Is there something that has to be done to the TPS to make it in fidelity with the PCM?

Thanks

 

Found this in the Neon forums good discussion about it...maybe this is it?

Many scan tools consider 0.00 volts to be 0% and 5.00 volts to be 100%. You should never see 5V going back to the PCM in a Neon unless the TPS is defective. You should see more like 3.8-4V. Probe the wire with a multimeter and you'll see the true voltage. The PCM sends 5 volts to the TPS. It is a simple variable resistor inside the TPS. 5V power, ground and signal wire that goes to the PCM. The PCM isn't looking for a "percentage" like you are seeing, it is looking for volts within a given range. If it sees close to 5V it will set a code and you'll see a check engine light.

5.00 volts x 78% = 3.9 volts at WOT

That's the way it's SUPPOSED to be.

Here is the thread I was reading...

http://forums.neons.org/viewtopic.php?t=311303

here is another excerpt...

The SBEC PCM recognizes Wide Open Throtte (WOT) when it sees the current TPS voltage at approximately 2.6 V above minimum TPS. What is minimum TPS? It is the TPS voltage seen with the throttle closed. Since the PCM learns the minimum TPS value with the engine running, there is no need to "adjust" the TPS as was commonly the case on other, inferior designs.

So, if your TPS reading is .75 v with the throttle closed, then WOT would be recognized at .75v + 2.6v = 3.35v. As Jeff said, the DRB III scan tool doesn't really display TPS as a percentage...because that's not how the PCM analyzes it. Please bear in mind that minimum TPS typically lives in the range of .5v to 1v. Also note that the PCM should always see a WOT TPS reading (minimum TPS + approx 2.6v) before the throttle has reached the WOT throttle stop.

Seems like that it the was it is supposed to be ??????