Ok First of all I know there is alot of info on this,But I do Not have the Time to Read a Million posts right now.I bought my wife a 99 Trans am.It has 4.15 V @ WOTHow can I get this sucker up to 4.5V atleast?I don't think I can get enough movement out of it if I do the TPS mod.Why would it have such little power,and how much power is this actually being lost?
Thanks!

 

Check to make sure that the TB plate is all the way open during WOT. Sometimes the cable is not adjusted properly & the TB does not fully open when the gas pedal is all the way down on the floor (WOT).

 

Exactly, check this first.

Now if the throttle blade is all the way open and hitting the bumpstop and you're still only getting 4.15V, then you'll need to do the throttle stop mod. Basically you gradually grind away at the throttle bump stop on the side of the throttle body until you get exactly 4.5V.

 

I'm sorry, but what's the purpose. If the throttle blade is parallel, What difference does the volts make?

 

Also, which wire are you testing for the volts?

 

That's our point, the throttle blade is likely not parallel. Typically, the TPS will read around 4.5 Volts when the plate is parallel (reference voltage from the PCM is 5V). So, we are suggesting that the position of the plate be checked, in order to see whether or not it is parallel. If the OP confirms that the plate is parallel @ 4.14 Volts & there are no codes "CEL," then it is OK. It is likely that the OP will find that the plate is not parallel @ WOT. There's nothing more to say until the OP replies.

 

Thanks for the Help Guys LS1-450 this was correct ,The Blade was not parallel when at 100% WOT.I did the TB Bump Stop and now we have 4.55v @ WOT.I Also have to adjust the Throttle Cable but Where do you Do that?I moved the throttle cable bracket for a temp fix to get tb to fully open @ wot.

 

You may have to remove the gas pedal arm and bend it
(done this with bench vise and a piece of pipe, seen one
car that despite snug cables would only pull to 85%).

 

I have the same problem with my LT1. My datalogger shows 4.04 volts at WOT and TPS 100%. Is it possible for the TPS to read 100% but the TB blades not be fully parallel?