1972 Chevy Monte Carlo Hard to start and appears to be floo

MATTSUE007

MEMBER
1972 CHEVROLET MONTE CARLO
V8
2WD
AUTOMATIC
68,800 MILES

I have a 400 small block with a Rochester Quadrajet Carb. Has run fine for a long time with no problems at all. All at once, I went to start the car one day and had a hard time getting it started. When I try to start and give it a little gas, and let off the key trying to start it, it has a burping noise coming from the carb. When I removed the air cleaner and did the same thing, I heard the burbing noise as well as observed gas spitting up from the carb.
As long as I am carefull and feather the gas pedal gently the engine will start right up and will run great, with no problems idle or running down the road. Problem only occurs when I start the car. Does not matter if the engine is warm or cold either, same results. I ahve done no modifications to anything that I would consider relative to this issue. I would believe a carb rebuild may be in order, but what is causing these symptoms?

1 Reply

HMAC300

MECHANIC
48,601 POSTS

Two things that I can think of. One would be teh needle and seat is sticking and after cgas flows through it it cleans up. Or the float which I think is plastic in your car has had the center eaten out by the alcohol in the fuel. A rebuild is in order it seems and check the float by having a pan of fuel and ut the float in it to see if it sinks. If it does, you'll need a new float which isn't in a carb kit. Make sure when having an open container of fuel around to work veyr safely around it, absolutel y no smoking or open flame, spark etc. Also if rebuilding the carb replace the fuel filter or if you have tow filters both of them