Wide open throttle at startup

[Dave77vette]

I just rebuilt my 77 corvette Quadrajet with cliff's rebuild kit and slapped it on my 383 stroker i just built.  I converted from hot air to electric choke.  I used cliff's kits and the third recipe from the book.  Im lost on what to do.  Everytime I start my car, i have to hold the primary air flap shut or the rpm's automatically jump up to about 6500.    Does anyone know what im doing wrong?  I backed out mixture screws 4 turns, and my APT screw one turn.  My sidepipes are blowing some eye burning black smoke.  I haven't been able to time it with the light due to my problem with getting it to idle.

Please, any advise will help, Im lost

[Cliff Ruggles]

Check the baseplate to make sure the primary and secondary throttle plates are closed at idle.

To run 6500rpm's, the carburetors throttle plate(s) would have to be open considerably....Cliff

[Schurkey]

Wildly out-of-adjustment fast idle screw?

Fast idle mechanism jammed or binding?

Lack of throttle return spring?  (got me last weekend...)

Linkage for secondaries caught/binding on something?