Carb tuning question...
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 7,218
Likes: 1
From: Cresskill NJ
Carb tuning question...
I posted this in OT already, but I figure this would also be a good place to ask even though it's not a Vette.
I've been working on getting the carb setup right on my Chevelle. Over the winter I put in an A/F gauge connected to an O2 sensor right in the collector. I now have #19 holes drilled in the throttle plates to lean out the idle and allow the idle set screws to actually have some control over the idle mix. I have been going by the amount of transfer slot exposed to determine when the holes are drilled big enough. No more then .04 of the slot should be exposed or the carb will start to draw from the primary circuit. Not quite there yet, but pretty close.
The thing that is really confusing me though is that the A/F gauge is reading right at stoich with an 800 RPM idle, but the exhaust still smells really rich. Am I missing something here?
I've been working on getting the carb setup right on my Chevelle. Over the winter I put in an A/F gauge connected to an O2 sensor right in the collector. I now have #19 holes drilled in the throttle plates to lean out the idle and allow the idle set screws to actually have some control over the idle mix. I have been going by the amount of transfer slot exposed to determine when the holes are drilled big enough. No more then .04 of the slot should be exposed or the carb will start to draw from the primary circuit. Not quite there yet, but pretty close.
The thing that is really confusing me though is that the A/F gauge is reading right at stoich with an 800 RPM idle, but the exhaust still smells really rich. Am I missing something here?
Le Mans Master
Joined: Feb 1999
Posts: 6,807
Likes: 0
From: Hoosier
Cruise-In III Veteran
Re: Carb tuning question... (DngrZne)
read the last page, it may answer the question. http://www.telusplanet.net/public/gi...d/carb_jet.htm
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 7,218
Likes: 1
From: Cresskill NJ
Re: Carb tuning question... (AlwaysWave)
"It is unreliable to use an O2 reading to adjust the idle mixture, use the
lean drop procedure in the manual for adjusting idle mixture."
I think that pretty much answers that..
Thanks
lean drop procedure in the manual for adjusting idle mixture."
I think that pretty much answers that..
Thanks
