Help how do I find vacuum leaks

[Tobywon]

HElP
I have a 914 2.0 injected. and it's hunting (idle oscillate up and down)
Sounds like a vacuum leak to me. So how do I find the leak?
Auxiliary air vale ??? Where is it ???
Any Help would be great

[Joe Ricard]

Some people use Propane
I prefer Starting fluid. Both are dangerous so be careful.

[JimHoyland]

Originally Posted by Joe Ricard

Some people use Propane
I prefer Starting fluid. Both are dangerous so be careful.

I used a couple of clear neopreme hoses from Home Deport and substituted one hose at a time.

My worst hoses were the small ones; kink one between you fingers. If it breaks, they are probly really old.

.02

[RandyLok]

Yes a vacuum leak. There are many potential sources... All below butterfly in the throttle body. Follow it through methodically. I've never had much luck with squirting crap at potential leaky places. But there's only so many places to trace. Seems like I've posted this a few times lately, so you are not alone in tracing this. Just think it through.... Where could a leak happen?
* Butterfly
* Vacuum retard port to dizzy, hose
* Throttle body to plenum gasket
* Leaky plenum (cracks tend to happen most often around the tubes that run top to bottom). Lots places to check on the plenum... Vacuum hoses, AAR, CSV, etc.
* Seals between plenum and intake runners
* Phenolic blocks between intake manifolds and heads
* Injector seals (two per injector)

Once again, I probably missed a spot. But the point is, follow the path. Any possible point air can get in, check it. If it is a spot that doesn't need air to idle under normal conditions, plug it and see if you note a change.

[Tobywon]

Thanks for the help I'll try some of these this week end and post results