Then it sounds to me as if the valve itself is OK. So either the control system is not able to supply vacuum to the valve or the feedback system is not sensing the change. I'll try to look it up on Alldata this week and let you know how your works, but I can't promise anything. We're a little understaffed right now, so I'm very busy. I've got a 55 Ford truck in right now with a Thunderbird 312, an Ofenhauser intake and three two barrels that my customer would really like to have back soon... he just picked up the intake and carbs. They look great, but leak badly and don't run worth a s**t.