Ok, I'm still working on my high idle problem when down shifting or coasting. I've got an auxilliary air regulator ordered but if that doesn't solve my problem my next step is the BCDD. If I have to replace this does anyone know where to buy one. I've yet to be able to locate one on the internet. I would appreciate any help in this.

Do you know if your car is a California car? If so, the problem you describe is quite common on them and would simply require an adjustment of the altitude switch.........if it's a California car. I hate to see you throwing parts at the problem.

it's not a CA car