Do you have a Vacuum Gauge? You can use it to tune-up your engine.
I use mine with a tachometer. Do you know what the readings mean?
Click the image below to download 3 pages
that will supply you with all the info you need!
You can also check the results against the interactive below.
THIS SHOULD BE ONLY USED AS A GUIDE.
SOMETIMES OTHER CIRCUMSTANCES CAN CAUSE
THE GAUGE TO ACT THE WAY IT DOES.