Looking for a little help here. I just rebuilt a 1976 Q-jet #17056512 for my 69 Firebird with a 462 Pontiac engine. bought Cliff's book and a kit from him. Cam duration is 239/247 @ .050", comp ratio is 12:1, ported #13 heads (flow 255cfm @28" H2o), 3.73 rear gears, 200R4 trans. Setup on carb is:
idle tubes .041
idle down channel .0635
upper air bleed .070
lower air bleed .070
idle bypass air .1065
mixture screw holes .1065
holes in plates none
main jet 77
primary rods 44
secondary hanger M
secondary rods DA
The engine idles slow 650 rpm and rough with 14 degrees of initial timing. Vacuum advance is disconnected. Engine pings with this much timing. Exhaust stinks too. turning in of the idle speed screw causes rich idle with black soot coming from tail pipes (nozzle drip?). Idle mixture screws will kill engine if turned all the way in. Seem happiest at 4 turns out (engine slightly speeds up at tip in). APT set at 3.5 turns out. I'm getting a terrible surging at 1400-1600 rpm in 4th (overdrive) with converter locked up. I'm working with the third recipe from the book. Why is it so difficult to get the idle rpm's up and a decent idle and what is causing the surging at cruise rpm's?
