Honda Repair: Cold start, vacuum leak, vacuum hose

Question
Hello, I have a 1987 civic 1500cc 3bbl carb with an automatic transmission. It SUDDENLY developed a cold start problem. when the engine is dead cold and I set the chock with the gas pedal the engine will start instantly and run for a moment and then act as if it has a huge vacuum leak and just die. You can repeat this process over and over or just play with the gas for a minute or so and then it will run fairly ok untill the engine is warmed up. when the engine has been run the car starts and runs fine. The choke sets when cold and unloads as the car warms up and I have pulled off the top of the carb and checked the needle and seat and float level. the carb is getting plenty of fuel. Also the car runs really sputtery until warm. now, one more item of interest is that on deceleration, always, you can hear and feel a pfut,pfut,pfut at the exhaust pipe. this did not occur prior to this cold start problem. I just replaced a rotted muffler and the exhaust feels un-restricted at the muffler. since there are no codes available and the o2 sensor is 19 years old, could this be the problem? egr valve? the pcv hose and valve are new. I have checked every single vacuum hose and all are like new and hooked up to their proper sources. This car is a sensor/valve/vac hose nightmare! Thanks for any help you can give me! Sincerely, Eric

Answer
I can help. . .

For starters these type of carbs crap out just like that, its not a vaccum problem its wear in the needle valve where the needle sits inside the carbs, i suggest to replace the carbs, and check the auto choke is set right, it sounds like the car is getting too much fuel at low revs when starting from cold, you will find that there will be a puff of black smoke when you start it, Write back and tell me how you get on ok

Cheers RUSTY