hello friends hoping you guys can help me with my problem my car (91civic dx sedan) recebtly developed a very rough idle while stopped at red lights with my foot on the brak the idle is very rough but when I take my foot off the brake the idle is fine . Anyone have a clue as to what could cause this ? the car is a 1.5 with a manual tranny thanks in advance

 

how rough is the idle. my car has always done that when i hit the brakes, but the idle isn't that bad and i live with it

 

you have a vacuum line that goes to your clutch master cylinder and it sounds like you have a leak internal which would cause the engine to idle rough when you have your foot on the brake... They are somewhat easy to fix if you have the right tools and replacement parts but about 50% of the time its just best to either get a junkyard unit or buy a new one