Easiest way to find a vacuum leak?

[briwayjones]

For a long time now my RPMs have stumbled at idle. I originally thought it was the plugs and wires as when it started I had 109000 on the plugs and wires. I changed the plugs, wires and cleaned the IAC and MAF sensor but it still does it. So I'm thinking there's a vacuum leak somewhere. I've poked around but can't find anything obvious in the way of cracked hoses or lines. How can I find the culprit?

 

[cybergasm]

Get a can of ether or carb spray and start spraying around vacuum lines or where ever you think the problem may be. If the RPM's raise after spraying the culprit then you found the problem.

 

[manaen]

Propane works better and is much less problematic on the electrical connections

Here is a good writup on vacuum leaks
http://www.aa1car.com/library/vacleak.htm