Hello, I am having diffuculty with my trucks idle. Its a 95 SIlverado, it only idles at about 600 rpms all the time. It does not stall like this but it concerns me. It has been chiped and I am currently only running 93 oct. It is also TBI. What could the problem be, I have troubleshooted and I am coming up with nothing. Could it be the throttle pos sensor or the idle pos sensor. I just cant understand what would cause this. Can I manually adjust the idle myself. Its not a vortec.