need info on 91 infinity Q45?

Question

dosent get over 3000 rpm wile driving

Answer 1

plugged exhaust, low fuel pressure, plugged air filter, bad mass air flow sensor, bad throttle cable or binding throttle plate,cam timing off,bad transmission, brakes stuck on, not pushing on the throttle far enough because the floor mat is jammed under the accellerator pedal. your seat is back to far so you can't push the throttle down far enough.
could be lots of things but there is a few things to check.

Answer 2

it could be many things speed sensor or the brain (the cars computer) but it most likely electrical.