Wow. It has been a long time since I've been on here. Hope someone has an idea to help. I run a QuickFuel 850 on my Riviera. Best pass is 12.71@106. The car runs great, except when I am cruising just off idle - like 35 - 40 MPH. Then it surges. Running 78/88 jets. A/F Ratio at idle is 14 or so. WOT is 13.0. When I am deep into the primary jets, doing basic around-town driving, the A/F Ratio is about 13.2 or so. When I am holding it JUST off-idle and cruising at 35 - 40 MPH it runs very lean - 17 or so. And my gas pedal is barely cracking open the primary blades at this speed. There is no need to put fatter jets in it, as it runs 13.2 when I am fully on the primary jets. So, is this an air bleed tune? Some kind of idle slot thing? It is pretty annoying to drive it while it is surging like it is. However, when it surges, if I JUST tick open the throttle a hair more, the A/F Ratio drops from 17 down to the 13's. It seems like the off-idle mix is very lean, but I don't know how to adjust that. Should I just run it really fat at idle and hope it covers the issue? Any ideas?