vacuum

[carlivar]

My 71 Riviera (455) doesn't run quite as smoothly as I'd like. I'm checking for vacuum leaks. I hooked up a vacuum gauge to the carb vacuum connector (manifold vacuum I believe) and I get about 18 psi while it's running. As soon as I turn the car off though the vacuum reading drops to zero instantly.

Is that normal or does it indicate a leak somewhere? I thought it meant leak but I'm not sure... I'm used to older cars where there's a vacuum connector right on the intake manifold rather than the carb.

Thanks!

[Greg Gessler]

Its normal for vac. to drop to zero when engine is turned off. Check for intake leak by spraying carb cleaner at intake and carb gasket surfaces. If engin RPM picks up or drops off, that would indicate a leak. Also check throttle shafts for excessive wear and leakage.

It may very well be timing and/or carb related. Good luck!

[sicksteve]

and plug all that crap for temp>timing> vacuum switch and all the smog ****, and any extraneous vacuum crap (Smog pump, etc.)

my '73 idles better than my lexus