Acceleration problem

[iabuell]

Ever since I had my Corvair I've had this sort of burping noise upon accelerating, and I would not gain speed till it stopped. Figuring it was the carbs, I got kits and rebuilt them. Now, the burping is reduced by about 30%, but it still happens. Anyone have an idea what I can do to get rid of it for good?

[bbodie52]

At first the hesitation you described sounded like a possible problem with the carburetor accelerator pumps. They squirt a burst of gasoline into each carburetor intake to smooth the transition from a closed to an open throttle. But since ou indicated you have rebuilt the carburetors but the problem remains, the fault may be elsewhere. To check the function of the accelerator pumps, the air cleaner assembly is removed. With the engine off and the choke held open, you should see a squirt of gasoline down the throat of each carburetor when you manually open the throttle. This action forces a small plunger within each carburetor to mechanically squirt a jet of fuel into each carburetor, which momentarily enriches the fuel/air mixture qhwn the throttle is opened. Without it, all the engine would get wold be a shot of air, minus gasoline, until the venturi effect can start drawing fuel from the carburetor float bowls to mix with the air.

If that is not your problem, you might look for a vacuum leak. The diagram below can be used as a guide.



Also check the vacuum advance that is mounted on the side of the distributor. You should be able to observe the mechanism move the distributor breaker plate as you rev the engine.

Once the engine comes up to speed after the hesitation you described, does it appear to run smoothly? Do you experience hesitation every time you step on the gas pedal? Are there any other symptoms you can describe?

[iabuell]

Its a lot better than before now that the carbs are rebuilt, but it seems to happen 1 in 20 times I accelerate.When the hesitation does occur, its only for at most 2 seconds and then the car will accelerate and run smoothly.