2003gtstang

I just bought a throttle body and plenum off of ebay. The plenum is stock but ported and the Tb is a profesional product andported. Last night i installed this. After it was all set i started my car. The rmps shot instanatally to 2800 rmp. That was what my car was idling at. So i went under the hood and checked everyhting and everything was fine. So i started it up again and right back to 2800 rmp.. So then i put the stock set up back on and my car was running normally again. We later came to conclusion that the Thtorrle body was making my car idle at 2800 rmp. so as of now i have a ported plenum withmystock Tb. Does anybody know what the problem is with the TB??????

Jbauer

The problem is you ported the PP Throttle body. Don't port an aftermarket throttle body! Heck don't port a stock plenum, the flow tests clearly show that as flowing less than the worse of plenums (I.E: Trickflow)
Go get a C&L or accufab or something. You can port the stock throttle body if you wish also..