hi, ive got a 75 stock 455 inmy 67 gs, currently with a 74 stage 1 q jet. the carb seems to make a sucking sound at idle that increases as rpms increase. i assume it is a vacuum leak but i tried spraying carb cleaner wherever i suspect there might be a leak and i dont notice a change in rpm. is this sucking sound normal? ive also tried changing in the rebuilt carb off of my 67 400 engine and it makes the same sucking sound. any ideas?
Is the sound present when the air cleaner is on? If it's off, then yes, it will make a huge sucking sound. Other than that, try looking at all the vacuum hoses and the brake booster vacuum hose. You may have a cracked hose somewhere. Also, if you have an open element air filter, the sucking noise will be more apparent with the air cleaner on than a stock cleaner.
actually the air cleaner is off when i hear the sucking sound, the only cleaner i have is the original star wars one so i usually keep it off of the car when im not driving it since i do not have a garage:ball: . thanks for the clarification.
