engine and drivetrain rpm changes when car gets driven

[1971Ginger]

So I've got a 008 distributor with a hot spark ignition. Engine was timed as best as possibke via timing light.

When I drive my car for a while, when I stop I notice my idle will fluctuate its rpm from 1000rpm to 1300rpm and up to 1500rpm. I know my distributor is tight and all sites have been looked over for good connection (I didn't run any volatege tests)

I was wondering what might cause this? I tried to set my air fuel mixture by rotating the screw on my 3236 and when turning the screw all the way in my engine didn't shut off. Do I have a vacumm leak?

I read PierreAlans. Posts about hot spark having a smaller dwell angles and thus I thought maybe its the electronic ignition.

Any advice would be appreciated.

[esty]

sounds more like a vacuum leak

[c.d.iesel]

yes a vacuum leak possibly - something wrong

the carb mounting insulator block/gaskets/loose?

burned? or messed up intake manifold-to-head

gaskets, rotten vac booster hose, bad vacuum

brake booster, missing rubber square o-ring

between brake master cyl. and booster ?

if your distributor has a mechanical advance

plate look to it's free, not sticking movement

advancing and springing back retarding function

That sticking causes your irratic RPM behavior.

if your carb linkage from the firewall is binding

and causing the carb throttle to crack open -

then that would be your cause for irratic idle speeds

happy hunting

[Hans]

do you have a return spring on the carb linkage?