So I have put on a new carburetor on my 73 cuda. When I hit the brakes and I'm at about 15 or less the car wants to cut off until I pump the gas. It even did this before I put a new carburetor on. When I put it in park it idles just fine, only when I'm going really slow is when this will happen. Also the metal hose coming off of the breather used to attach to a metal portion that was on the side of the engine. The mechanic said it was rusted off and took it off and did not give me the part back, even though I said to put any part you take off I want in a box. Sorry for not using the correct terminology, I'm trying to find out what its called and if I can even get a new one to put on. I know its not really needed to function but it was on there before.
Is it the air heater you are missing ?
Yes it is
Usually when the engine tries to die on sudden braking, it is the fuel level being a little too high inside the carburetor. It would probably be more noticeable at slow speeds because it's much easier to suddenly slow a slow moving car than one going fast. If this is actually your problem, the fuel spills over inside the carb and floods the inside of the intake manifold momentarily. The fact that it recovers when you pump it makes me think it is recovering because the throttle blades are being opened and that lets the engine have more air which helps it recover from the rich condition.
My car when i first got it will stall when i brake hard or slow down and turn. Some members suggested that my car has a vacuum leak. Pick up a vacuum gauge to tune the carb. If everything checks out, drive with the vacuum gauge inside the car and watch what it does when slow down and brake. If you have a vacuum brake booster, that can be a source for leak.
Quote from: 7212Mopar on June 04, 2020, 09:46:53 PM
My car when i first got it will stall when i brake hard or slow down and turn. Some members suggested that my car has a vacuum leak. Pick up a vacuum gauge to tune the carb. If everything checks out, drive with the vacuum gauge inside the car and watch what it does when slow down and brake. If you have a vacuum brake booster, that can be a source for leak.
When I read the OP's post my first thought was vacuum leak.
What was the solution to your issue
@7212Mopar (https://forum.e-bodies.org/mlist/7212mopar_441) ?
I replaced all the vacuum lines including the one to the power brake booster. That line took me awhile to find and finally got it from NAPA. I kept the lines for the AC, they looked ok. Change the mounting gasket for the carb and check and tighten the manifold bolts. I then play with tuning the carb with a vacuum gauge. All of that helped to a point that the car will not stall but idle still drop a lot under heavy braking. The problem went away completely after I upgraded with a new carb and intake manifold.
What kind of carburetor do you have?