quick question. When I'm tuning my carbs and setting idle, I often get them to a point where they are idling great, but when I rev the motor with the throttle linkage, the idle drops and acts like it's being "retrained" for a second or so, then the idle revs up fully. I get this condition frequently as I try to get the carbs synched and the idle set down to 900. I suspect that it might be starving, but the subsequent high rev has me confused. Plus, when I set the carbs any richer, it tends to diesel when I shut the car down.

I realize that this is probably pretty basic, but it's been bugging me that I can't say what going on for sure.

B20E with Dual HIF6 carbs (both fully rebuilt) BAL needles, o-ring thottle shaft seals, smooth throttle plates, extra vacuum port plugged.