accelerator pump c2 1964 carter afb carb

[Ted K.]

Accelerator pump for AFB carter carb on 300 hp 1964 Vette. Rebuilt carb because accelerator pump wasn't working. Old pump leather was curled up. Pump worked, test drove car and pump stopped working. Took apart,leather was curled up. Replaced it again with new pump, worked initially, but then stopped. Pump sometimes stays down in chamber, probably when leather is possibly curling/binding.
Any suggestions?

[Clem Z.]

Re: accelerator pump c2 1964 carter afb carb

soak the leather in oil before inserting into the carb

[Christopher R.]

Re: accelerator pump c2 1964 carter afb carb

I don't know why it would do that. There's thousands of them in service that don't do that. Maybe you're unlucky and got a couple of bad ones in a row. The leather needs to be wet in order to work. Lots of them dry out when the gas in the carb bowl evaporates while the car is in storage. But they usually reconstitute themselves quickly after gas gets back in the bowl.

Edelbrock and/or Carter offer a marine version of this pump piston. It comes with a neoprene skirt instead of leather. Maybe that'd help. You can get the part number from the Edelbrock Web site, and order it from your local speed shop or Jegs, Summit, etc.. Don't know if that'd create more problems than it solves though.

The leather skirted pump comes in rebuild kits. But you can also get it separately. You can also look for that part number on the Edelbrock Web site. Don't forget that you might need the big gasket that seals the 2 halves of the carb. So by the time you buy a pump and a gasket, it might cost more than a rebuild kit which contains both. You can usually get the carb apart (to replace the acclerator pump, say) without wrecking the gasket if you're careful. To increase your odds of saving the gasket, spray both sides of it with silicone, or lightly coat it with grease, when you reinstall it. I carry a $35 carb rebuild kit in my spare parts kit in the trunk.

[Timothy B.]

Re: accelerator pump c2 1964 carter afb carb

Ted,

One thing you might want to check is the pump inlet check valve and see if it's allowing fuel into the pump cavity. The check valve looks like a carburetor jet and could be stuck closed due to dirt and not allowing enough fuel to enter the pump well. This condition might cause the leather on the pump plunger to get hot and curl as you describe. The check valve is located at the base of the pump well and lets fuel in when the plunger is drawn up and closes when the pump is pushed down. Hope this helps you , Tim Barbieri

[Ted K.]

Re: accelerator pump c2 1964 carter afb carb

Fuel is getting in through the check valve, but when I rebuilt the carb I tried to get the check valve out and was unsuccessful. It does look like a carb jet but apparently doesn't come new with a rebuild kit. How does the check valve work? Could it be working intermitently?

[Clem Z.]

check pump bore

make sure the pump bore is smooth with no ridges.

[Les Jacobs]

Re: accelerator pump c2 1964 carter afb carb

Grasping at straws here..but is there a spring in the bottom of the pump well? Some kits do include the check valve. Thecarburetorshop.com does for example. Pls post your results. Good Luck