Packard Forum Index » V-8 (1955-56)

The list of issues include
Hard restart hot in hot temps
Hard restart cold after sitting more than 3 days
Stumble on accell
Stagnent fuel in secondary bowl
Drip from throttle shafts
Secondary throttle not fully returning
Accel pump issues
Extreme fuel vapor/ fuel smell upon parking in garage
Has anyone had one or more of these? I had experienced 2 of them before retrofit or newer carb. If one performs a web search seems 55 buick and cad owners have similar.
Also see other threads here:packardinfo.com/xoops/html/modules/newbb ... lat&order=ASC&type=&mode=0&start=20

Thanks for elaborating. Of your list all I can relate to is hard starting cold but not after 3 days, more like 10-14 days. And that's more a function of today's fuel than a shortcoming of the carburetor. Perhaps I have stagnant fuel in the secondary fuel bowl but since I almost never open all 8 ventures I wouldn't know. Other than that I'm not experiencing what you are.

I took a quick look at the posts in the thread you cited. Many folks are reporting excellent performance; whose who aren't seem to have a mix of incorrect carburetors, mongrelized carburetors, or dubious rebuilds.

Exactly what 4GC problems are you experiencing and what is the history of carburetor?

The carb that was on the car when we got it was the orig one I believe. I say this because of the evidence of all components shown upon removal and all #s and markings on items and my experience. The carb had a small tag on it very different from the ones shown on another thread here and it has #s stamped on an area of the air horn that confirm the last four of the part number in an area easily overlooked but most assuridly identicle to other originals. In fact they had been overlooked by me in 09. I am having no issues with it as it has been on the shelf since 2010. I am running a more modern Demon and I can easily let the car sit 4,5 or more weeks and start it without issue. I know the fuel blends are compoundung some issues but the difference in performance of the GC compared to others seems to be suspect. I was wondering with float assm now available if others are satisfied with the carb.

I did see the post by Jack and was wondering how much research and fine tuning has been done esp with the wide band O2?
I was experiencing hard restart hot and a no start after 5-8 days sitting depending on conditions which is certainly unacceptable for almost everyone.

Quote:

With the two 1x4 Rochesters rebuilt by Daytona, the only problem on your list I've experienced is secondary throttle not returning to full close every time.

They start at a touch, hot or cold. I am using an electric fuel pump, which probably makes a big difference.

FWIW, the meter shows the cruise air/fuel ratio is very good. The problem is trying to tune and adjust four screws and eight idle circuits. That's what sucks up the fuel and that's why the factory disabled the secondary idle circuits.

jack vines

I know it's not original, but EZ EFI makes a dual quad EFI setup that will work and solve all your problems with the carbs. I plan on this with my car when I put the dual intake in it, but mine isn't a Caribbean either.

I know it's not original, but EZ EFI makes a dual quad EFI setup that will work and solve all your problems with the carbs. I plan on this with my car when I put the dual intake in it, but mine isn't a Caribbean either.

Yes, I was wondering which issues were repairable and which are inherent design issues with the carb? So the electric pump to prime is the only real answer to the 12 day no start? Maybe a full examination of the subject will help others decide as to attempt a rebuild or send out or retrofit. I spoke to tim and got some info but maybe there is are more updates. I was asked by an interested party why I was not using the orig carb. Would a car be more marketable with the orig carb or running and drivivn more easily?

Jack I think the secondary idle bleeds are fed from small holes in the primary sides through a channel around the bores and through holes in the bowl gasket . Couldnt you just cut a new gasket and eliminate these holes to eliminate secondary idle fuel fot testing on a 2X4? Just go back to the precut gasket if too lean? I thought you were running carbs you personally went through not daytona stk remans.

Edit: sorry- upon closer examination, the secondary idle fuel can only be eliminated by plugging the brass cup plugs in the sec side of the base as the gasket holes need to remian so as not to disable fuel to 2 upper idle discharges in part throttle operation. Doable but quite a bit more involved.

As far as the secondary throttle blades returning, I was quite surprised by how light the spring is on these and though the base is cast and most low miles cars will exhibit very little wear in the secondary bores they may be sensitive to rust on these springs and critical alignment of the blade discs if they were unscrewed from the shaft for rebuild.