My Suburban is idling high after I changed the idle control valve. It still dies when in drive and won't accelerate when I push the gas pedal.
The symptoms that you are experiencing with your Chevy have lead me to believe that your Suburban is experiencing issues with its’ Throttle Position Sensor (TPS). If the TPS is failing, it will duplicate many of the symptoms that have been described. This is due to the TPS not knowing where the position of the throttle plate is inside the throttle body. However to be 100% certain of this diagnosis, it may be time to enlist the assistance of a certified mechanic to stop by and go over your vehicle with you. They will be able to diagnose why your Chevy is experiencing a high idle and trouble accelerating and provide the necessary repairs needed to get your Suburban running tip top again.