On my 1992 olds the car has a rough idle like a vacuum leak so i started looking at vacuum lines. When i take the vacuum line off the charcoal canister the idle smooths right out. whats my problem the purge solenoid? Plus the car will start to run really rough and stall out at stoplights sometimes but start right back up

and when i took the vacuum line off i just left it to suck air and thats when it smoothed out