Thats odd , idle mine reads from 1-5% , full throttle reads 95-99% given the 1%+/- , now im curious , im gonna take tps reading from different cars and see , i know with advanceauto , partsamerica tps reading from them are weird , i have a tps from the dealer and it reads from 95-99% full throttle...

 

Keep it. It maybe more accurate than most. The tps is basically a potentiometer. You have a input voltage from the pcm of 5v and it outputs a low voltage at closed throttle and high voltage at wot. It should never read 0 or 5. Because of variances in manufacturing from one company to the next, or even production runs from the same company, the sensors will vary in what they read at either end, and you also can (as in your case apparently) get a wider or narrowerspectrum of voltages from sensor to sensor. The pcm learns very quickly what the limits are. Mine goes from 14%-76%. IIRC it was made by Standard Parts. The programming doesn't seem to be real straight forward either. You would think that because14% of 5v is .7v the tps should read .7v at idle. This isn't the case either.

Edit: 0v and 5v will both throw codes in the 220's

 

plus with the programming, there is a way to set a "learned" point. You can unhook the battery and before you turn the key depress the throttle a certain amount and it will store that point in the computer IIRC. I know its possible, just been a while since i did it. And keep in mind that the sensor will never read 0% because there is a preload when the sensor is put on. You have to put it on the valvebody shaft and turn it 3-7degrees or so. Depending on how you turn it depends on what your base is most likely going to be. Also, a popular mod for a TPS is to set the idle voltage in reference to the input voltage at .76volts and it offers better throttle response...most likely due to fuel curves.

 

For some reason, the tps mod (sorry if that doesn't qualify Indy)seems to work better for some than for others. It may have to do model year and programming. I've heard people rave about it, and I've heard where it didn't do chit for others. I guess if you truly want to understand it all a-z, it'd be best to go down to Longwood and take the class.

 

I think the TPS mod mod-diddy mod mod depends more on the TPS manufacturer than the Truck. When I modded the stocker I noticed a big difference. 4 months later it blew out. I modded the new one and when I tried to set the new one to the old .74 volts, it threw the TPS voltage too high/out of range code.