CarburetorsCarb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.
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(just got it yesterday by the way, very happy to be a third gen camaro guy now!)
now onto business.
my 4bbl quadrajet is running rich. how do I set it so it isnt running so rich? i looked at the sticky but I need it to be explained in common terms cuz im a little slow. lol have never worked with carbs before but i would like to learn and idk anybody who knows that much about them so a little help would be appriciated.(im 18 and all my freinds drive fuel injected unfortunately for me) if you could be as specific as possible with things like the location of adjustment screws and things that would be great. thanks in advance.
First question- how do you know it's running rich, and is it across the rpm range? There are multiple fuel circuits in the carb which control fuel mixture at different throttle positions and engine loads. Does it seem to run rich at startup, and lean out os it gets warm? Does it bog down when at wide open throttle (WOT)? Read up on the quadrajet, if you are unlucky it is one of the electronic ones and these can be difficult to tune. You might consider an upgrade to another carb/intake which will net you more power and easier tunability. By most accounts, Holly and Edelbrock carbs are easier to work with and both will give you power gains, possably effiency gains as well.
__________________ -Berlinetta00-
USMC Motor Transport
'84 Berlinetta
'00 Ford F-250 Diesel
'71 Scout 800B
Check it with a WBO2 to confirm it's rich and by how much.
If it just smells rich, it might not be.
You need to eliminate ignition problems and misfires first.
If it's the carb, then check for fuel leaks before changing the jets.
well i havent checked it with a volt meter or plugs or anything like that but the exhaust has a lot of moisture in it and smells like gas it alsmost seems like if i put a lighter to it it would shoot fire. it seems to idle rough at start up and then goes away after it warms up. could it possibly be the choke?
also,it does not bog a wot
Last edited by aciddrop2804; 04-01-2009 at 01:39 PM.
The cold start rough running sounds like the choke pull-off ("vacuum break" in GM-speak) either not adjusted properly or not operating properly. Easy way to check that is, with the engine cold, remove the air cleaner and plug the vacuum nipple that the hose going to the air cleaner connects to. Open the throttle enough for the choke to fully close. Start the engine, the choke pull-off should pull "in" and slightly open the choke butterfly. If it doesn't open enough or opens too far, idle quality will suffer. As the engine continues to run and warm up, the choke butterfly should gradually fully open. If it does not, that's your rich condition.
If the choke is fully opening and it seems rich when fully warm, you might have a weak O2 sensor. Is the SES light coming on?