Were the carb bowls empty? When the gas evaporates in fall, it leaves behind solids that can plug your idle wells.
If yes; then I think the metering blocks will have to be torn down and boiled in carb cleaner to clear the passages you cannot see.
If you did not stabilize the gas last fall, then take a sample, and check the color; clear is good, red is bad. Orange/pink is iffy, you can burn it in your lawn moper; but not in your boat or chainsaw. Yellow is occasionally hard to start, but OK at Part Throttle.
If your car was stored in a non-heated place, then the fuel tank breathes all winter thru the vent. More if left outside in the sun. The breathing brings in moisture that is in the atmosphere...... which condenses, and collects in the bottom of the tank and freezes to ice. In spring it melts back to water and is the first thing your fuel pump sends to the carb.
