First Generation Firebird-L Mailing List ......................................................................... Danny,
I recently just put a PC up in my garage too, it really is a good resource. And you can play MP3 files through the speakers while you work. :) Are you sure the Q-Jet on your car is indeed the original carb. There are many styles of Q-Jets out there, and each one is a little different. If you can, take some pics of it, or read the 7-8 digit number that is stamped vertically up the carb on the drivers side right next to the secondaries. You can decode this number to tell the year, if it is a Pontiac, Buick, Chevy, and then what options the car had. For instance, I had a '73 Olds marine Q-Jet on my car for over a year. The one vacuum port at the bottom back of the carb is the main manifold vacuum that usually goes straight to the booster. Maybe someone else can tell you more about the TVS, I don't know enough about that. The one thing about GM back then...you can never say "always" or "never". Things just "got done" on the line and a lot of the time, there was no documentation. Just ask the POCI guys who have been researching for years when the actual date Pontiac started putting a radial tire on cars in the factory. Thomas -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of D Dutch Sent: Wednesday, September 02, 2009 9:41 AM To: First Generation Firebird-L Subject: Re: [FGF] Vacuum Madness First Generation Firebird-L Mailing List ......................................................................... Thanks Thomas, I did quite a bit of searching before posting here but I guess I just wasn't typing the right search terms to come up with the right info. I appreciate your knowledge. The link you sent was informative but isn't quite getting me the answer. - There is only one vacuum port on the back of the carb, dead center below the throttle body at the base of the carb. - I wouldn't have thought anything strange about the vacuum going straight from the carb to the distrib. advance except that the service manual info, and other stuff I have found has the vacuum going from the TVS to the advance port on the distributor and not straight from the carb. Thanks for helping a Firebird newbie (and a carb newbie). I'll keep doing internet searches as well. Just setup a PC in the garage high on the workbench at the front of the car so I can look stuff up without running in and out or having to print things. :) Danny Dutch [email protected] On Wed, Sep 2, 2009 at 3:28 AM, Thomas R. <[email protected]> wrote: First Generation Firebird-L Mailing List ......................................................................... Danny, On a Quadrajet, the lower port on the front driver's side the hookup for "ported vacuum", and it commonly goes straight to the distributor only. This ported vacuum lies above the throttle blades, therefore, at idle, this port has no vacuum, since the throttle blades are closed; and hence it does NOT pull your vacuum advance ahead. But, when you press on the accelerator, the blades open up, vacuum is then present at this port, and then your distributor kicks in the vacuum advance. The port on the back of the carb at the base is "manifold vacuum". This is always on. This gets hooked up to your brake booster, or any other device in the car that always needs vacuum. The hard line to your trans should be for your TH-400 tranny vacuum modulator. The other port at the back should go to your secondaries choke pull-off. Read this thread for more info: http://www.chevytalk.org/fusionbb/showtopic.php?tid/214605/ Not to say we can't help you, but there is a WEALTH of information at your fingertips on the Internet. Utilize Google or any search engine to look for info, which is how I found the article above. Search "quadrajet ported vs manifold vacuum." Remember, lots of these GM cars have similar parts, so you don't necessarily need a Firebird manual. Ciao, Thomas ------------------------------------------------------------------------ Submissions to Firebird-L: <[email protected]> Unsubscribe from Firebird-L: <[email protected]> Help: <http://FirstGenFirebird.org/firebird/Firebird-L.html> Classifieds: <http://FirstGenFirebird.org/ubb/> Owner Pictures: <http://FirstGenFirebird.org/show/> ------------------------------------------------------------------------ Submissions to Firebird-L: <[email protected]> Unsubscribe from Firebird-L: <[email protected]> Help: <http://FirstGenFirebird.org/firebird/Firebird-L.html> Classifieds: <http://FirstGenFirebird.org/ubb/> Owner Pictures: <http://FirstGenFirebird.org/show/>
