gradedcatfood
1972 Plymouth Duster 440
Hey everyone, I have a Holley 750 Double pumper with mechanical secondaries and i'm having a carb tuning problem.
I'f i'm cruising in 3rd gear, punch it, the car will downshift but will have an initial lean spike (up to 16-17 AFR) but will then settle back down to 12-13 AFR within a second or two. Also, it will backfire through the carb.
Is that something to worry about? I was thinking that maybe it needs a different power valve but I'm not sure if I would need to replace the one on the primary or secondary side (maybe both?)
This seems to be the only issue while driving as all other driving conditions yield a consistent and steady AFR of about 11-12 AFR. For example, from a dead stop, if I punch it all the way through the gears its totally fine.
I'm a bit of a newbie with it comes to carbs so any advice is appreciated. Thanks
I'f i'm cruising in 3rd gear, punch it, the car will downshift but will have an initial lean spike (up to 16-17 AFR) but will then settle back down to 12-13 AFR within a second or two. Also, it will backfire through the carb.
Is that something to worry about? I was thinking that maybe it needs a different power valve but I'm not sure if I would need to replace the one on the primary or secondary side (maybe both?)
This seems to be the only issue while driving as all other driving conditions yield a consistent and steady AFR of about 11-12 AFR. For example, from a dead stop, if I punch it all the way through the gears its totally fine.
I'm a bit of a newbie with it comes to carbs so any advice is appreciated. Thanks
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