Hi Gary, If I'm reading your post correctly, you say you have an Edelbrock 650 carb. This may not fix your lack of vacuum, but as far as being able to adjust your idle it may help.
With the engine off, remove both idle mixture screws and using either compressed air, carb cleaner, or even WD-40, blow the the idle screw holes out. A while back I was having a hard time adjusting the idle on my Elky (Edelbrock 750) and after cleaning the holes the idle speed would actually change as I adjusted the screws. Herb Lumpp http://users.adelphia.net/~hlump/ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Zieg72 Sent: Monday, August 18, 2003 3:43 PM To: [EMAIL PROTECTED] Subject: Re: [Chevelle-list] Low Vacuum I had a similar problem and it turned out to be the wrong size something in the carb. What ever parts control the idle circuit. It sounded like a pretty healthy durationed cam but when the carb was overhauled the engine had great vacuum and idled stock as could be. It did exactly what you are describing as far as running and all and having low vacuum. Just something to think on. ----- Original Message ----- From: "Gary W. Treible" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, August 18, 2003 10:59 AM Subject: [Chevelle-list] Low Vacuum > I recently converted my car from manual brakes to power. They work, but I > don't get the kind of assist I would like, so I got the vacuum gauge out and > took some measurements. I barely get 10 inches of mercury at idle (the spec > I think is something like 17). My engine is a 327 out of a 1967 Corvette. > A previous owner added a Edelbrock performer series intake and 650 cfm carb. > Judging from the idle, I doubt very much that the car has any kind of > radical cam in it. > > Using my vacuum gauge, I systematically went around the carb and the intake > individually pulling hoses and blocking that port, looking for leaks. I > still get about 10 inches (unsteady). I then tried the trick of spraying > carb cleaner around the base of the carb, and the runners on the intake > looking for a change in operation. I didn't see any. > > A friend told me to check the idle screws. When I tried that, I found that > I could slow the idle speed if they were near closed, but once opened up a > bit I get the same basic idle speed (and vacuum) over a very wide range of > adjustment. I was actually afraid the screw would come out. > > This has morphed from being a brake issue to being a "is my engine OK" > issue. What has me a bit confused is that the stinking thing runs pretty > well. I seem to have lots of power, and the idle is reasonably smooth. > It'll idle in the driveway all day and not stall. > > Does anybody have any ideas. I want to paint this car, and want all the > mechanical issues taken care of before then. If I need to pull the heads, > now is the time. > > Gary > > > _______________________________________________ > Chevelle-list mailing list > [EMAIL PROTECTED] > http://chevelles.net/mailman/listinfo/chevelle-list_chevelles.net _______________________________________________ Chevelle-list mailing list [EMAIL PROTECTED] http://chevelles.net/mailman/listinfo/chevelle-list_chevelles.net _______________________________________________ Chevelle-list mailing list [EMAIL PROTECTED] http://chevelles.net/mailman/listinfo/chevelle-list_chevelles.net
