vacuum test
Can someone tell me what it means when setting idle and you punch the gas and the needle on the vacuum gauge doesnt go all the way to 0.What does this mean?I have reved it as high as 3000rpms and it d...
Forum Discussion
probably doesn't mean anything except that the port you're plugged into is ported vacuum (right in the venturi or very close) Or if the air filter is still installed it might be restricted.
Remember the pistons going down are trying to pull the air in through the carburetor and the butterfly in the carburetor is restricting the airflow causing a vacuum between those two points. When you floor the accelerator pedal the butterfly goes wide open and the air rushes into the manifold faster than the pistons can pull it out so the vacuum goes to zero until the engine catches up.
Remember the pistons going down are trying to pull the air in through the carburetor and the butterfly in the carburetor is restricting the airflow causing a vacuum between those two points. When you floor the accelerator pedal the butterfly goes wide open and the air rushes into the manifold faster than the pistons can pull it out so the vacuum goes to zero until the engine catches up.
