Just bought a 1978 Cutlass Supreme with a Chevy 305 and a Rochester Quadrajet with hot air choke. First disclaimer, I am only 24yrs old and a Carburetor "newbie" so I'll do my best. Bought the car a couple weeks ago and drove it a few times since then; about 60 miles total. Drove and ran perfectly fine, smooth idle and no smoke. Last time I drove it, it started up fine and idle was ideal. Put it in drive and got on the trottle (basically to the floor) for about 5 seconds and then let off, car continued to accelerate and had to work the brakes home. Now, every time i start it up, it runs higher than supposed to (my guess would be 1000-1200 rpms, and also very rich, strong gas smell with some white smoke from exhaust). I have checked for vacuum leaks, sprayed down all linkage (throttle, choke, fast idle), throttle cable is not sticking, return springs have enough tension. Another note is the throttle linkage is not making contact with the idle adjustment screw on the driver side carburetor. I can force it down (pulling towards the grill) but it is tough. My guess the throttle plates are sticking? Like I said before I am new to carburetors and appreciate the help!