decceration stalling issues

[911buff]

My '71 T with Zeniths and a Bosch dizzy wants to stall when I come to a stop. it will immediately restart and idle as designed. I adjusted the idle circuit (1/4 turn richer) but no change. It is more pronounced when coming to a hard stop. If I slow down at a gradual pace, it will stay running but the idle is low and then comes up to ~900 RPMs. Any ideas?

[Porboynz]

Does it do it when you come to a stop out of gear but braking hard? If so suspect the float levels allowing fuel to slop into the intakes on braking. If you are downshifting through the gears then its probably vacuum related, high intake vacuum causing to much advance/retard

[911buff]

It does it out of gear. That gives me something to check. Thank you!

[porschetub]

Originally Posted by Porboynz

Does it do it when you come to a stop out of gear but braking hard? If so suspect the float levels allowing fuel to slop into the intakes on braking. If you are downshifting through the gears then its probably vacuum related, high intake vacuum causing to much advance/retard

X2 on that ,but bowl flooding would also cause a poor idle....surely.

[jwakil]

I have the same issue periodically on a 81' 930. Obviously we have totally different fuel systems with same issue. The part that sucks is it doesn't do it all the time, but usually when the car has been sitting a few days. Even then, it is kind of periodic and tough to diagnose. Some stop lights it will stall, others its fine. After complete warmup the problem goes away. Is this similar to yours? I have my deceleration valve removed, but if that was the problem I would suspect issues all the time.