68/9 200ci + Carter YF 1bbl + c4 = Rough Idle

I had a 68/9 200ci (and head) completely rebuilt, bumped up the cam a little and paired it with a rebuilt c4 for my '60 Tudor... trouble now is no matter what we do we can't get the Carter YF 1bbl carb to tune properly.

We've thrown a couple of kits at the carb, tuned the timing up and down, double checked the tranny... and it still idles too high at a stop. If we manually put the car in neutral it's fine but if I keep it in gear at a stop light it idles high eventually loads up and wants to stall.

Any ideas?

I'm not totally clear on how they work but some carbs have an anti-stall dashpot that has something to do with automatics and how the idle comes down when you come to a stop. Maybe it's not working properly. Or I could be totally off.

I'm just trying to think of what has a relationship to shifting and idle speed. It sounds like you've focused on the carb so maybe check the basics of the tranny if you haven't already. Clean filter, correct fluid type & level, valve body working properly, bands adjusted to spec, etc.

Sorry I couldn't be more specific but hope that leads you to some solution you hadn't thought of.

Oooohhhh... You make a good point with the anti-stall dashpot. The carburetor that we have on the car doesn't have one! Previously the car had the 2-speed Ford-o-Matic on it and that combo worked great... but now with the c4... I think you're on to something!

I'm going to have to start looking for a more modern carb that's equipped with the dashpot. :) Thank you!!

All a dashpot does is keep the engine from decellerating too quickly, since the torque converter is sort of like a clutch you can't press. If you are at the stop already, and it is still idling high - it's not that. Not that you don't need one, but the symptom would be stalling as soon as you let your foot off the gas. And that's not the symptom.

Have you checked vacuum readings? I assume you can lower the idle, but in doing so the engine dies in gear? What's the spec on the cam?