I have a 94 chevy s10, it was running like **** so I had done a tune up, replaced the cab rotor plugs wires, and fuel filter. I have also just replaced the battery alternator and starter all in a 6 month time. When the truck is in idle it runs great but soon as I touch the gas peddle its the rpms jump all over the place. If I drive and hold the peddle in a stationary spot it runs fine but the soon as I let go it starts to jump all over again. The truck does not back fire, to me sounds like the Throttle position sensor but it gives me the code 23 witch is the knock sensor could it be so.