Join Date: Mar 2002
Location: Austin, TX, USA
I had the same problem on mine recently. Turned out I hadn't given the linkage enough play to return to idle. What happens if you disconnect the throttle linkage all together? Otherwise I agree with ZZ430DropTop67RS. Check out the secondary stop. Should be between 1 and 2 turns out (your milage may vary). But if you get too far outside of that range I'd bet on a vacuum leak.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI