What are some good ways to check for vacuum leaks? I have deduced with various tests that the problem I'm having with my Z28 is it has a vacuum leak but I don't know of many ways to find one. I know of a couple but one hasn't worked and the other one I can't do. Someone told me you could spray carburator cleaner around the intake manifold and vacuum hoses while it's running and it should idle up when you find the leak. I did this with throttle body cleaner and found nothing. I was also told you can do a smoke test where you take some machine that pressurizesthe engine and fills it with smoke and the smoke will come out of where ever it's leaking but I don't have the stuff to do that and I was told it was an expensive kit.

Are there some other ways to check for one? I have looked for obvious leaks and there are none so now I need some advanced technique.

 

modern cars don't respond real well to carb spray...the computer compensates so much for the extra "fuel",its hard to tell..

most guys just listen...and watch the fuel trim readings on a scanner

 

But I don't have a scanner and I can't take it anywhere that has a scanner cause you can't drive it like this. Well I guess I'll try throttle body cleaner again then.

 

Checking them one by one will suck, but it is prob better than the intake cleaner stuff. Your idea might not work as well just because Im pretty sure the intake cleaner isn't nearly as flammable as carb cleaner. ( I could be wrong ). I'd start checking where the vacuum line connect to the engine. The majority of vacuum problems I have had was directly related to the lines splitting where they connect to the intake or engine. Just a thought.

 

Try either starting fluid....if it gets even close to a vacuum leak the idle will increase instantly....I`ve done it for years.