2001 Pontiac Grand Am THROTTLE / REVVING issues!

I have a Pontiac Grand Am GT with a 3.4L with about 200k.

Engine was running fine one day back in October 2015, then one day the Serpentine belt snapped. The A/C compressor had seized. I replaced it with a dummy pulley kit to eliminate the compressor altogether.

A short period later, the engine started running funny, and it continues to run the same way to this day. I will not drive it like this, for fear that I could drop a tranny.

When I start the car, it cranks just fine and starts. Once started, the engine revvs up immediately, and “bounces” between 3k and 4k on the tach. Almost as if someone is pushing the accelerator at 1 second intervals. It is a steady and constant rev up and down, once every second. It only revvs between 3k and 4k, back and forth, until you shut down the engine or it blows up. I have not put it into drive for fear of dropping a tranny.

I have taken a look under the hood, and checked the cable from the accelerator pedal, and also the cable from the cruise control box to the throttle body. Neither of these cables are moving the throttle, and the car never settles into an idle.

I have replaced the Mass Airflow Sensor, Throttle Position Sensor, and have also replaced the “marker-sized” airflow sensor that plugs right into the black plastic air intake tube to the throttle. None of which seem to make a difference or fix the problem.

Everything else seems to run fine with no apparent issues. Could it be an air intake issue? Or would that cause erratic and uneven revving? This is constant and even. Help, I need to sell this car, and this issue is preventing me from doing that.

I have a short video in MP4 format of the engine revving, but I can’t upload it here apparently. I can easily email it to your inbox, if requested. I APPRECIATE YOUR HELP!