I am in the process of checking for vacuum leaks on my car and some one told me that I should spray brake cleaner all over the top of my engine when it is running and if I have a vacuum leak my engine would rev even more than it is. The problem is going to still be trying to find it!?!?!?

 

You can also use a stethoscope (sp?) to narrow down your search. Just put it up to one of your vac lines and listen for a hissing noise.
I'm looking for vac leaks as well and i have this stethoscope that has this big needle thing at the end instead of that flat piece u use to listen to people's hearts. I have yet to locate my vac leak tho.

 

If you want to look without spending any money, use water from a garden hose. Move the hose from line to line...

 

or starting fluid

 

you can use carb cleaner.

when the car is running at idle just spray some carb cleaner on one hose at a time. if the idle drops, you found a leaky hose. the carb cleaner will act as a sealer for the hole for a few seconds then dry off.

info provided by wackyracer