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Discussion Starter · #1 · (Edited)
The 3810 Holley on L79 corvette wants to stall out as coming to a stop. Other than than seems to run great. Idles nice at 750, translot is square, non showing on secondary’s. Engine hates having secondaries open a crack. Changes include rear meter block conversion, primary IFR at .028“ front and rear. Rear plate IFR was .028” and front was .031”. But the stink was bad. IAB was .070” now .062” in attempt to not alter ratio too much.
MAB‘s remain at .031”. Screws out 1 1/2 seems to like setting. Still have hydraulic Comp 270 grind cam & HEI. Bumped timing up to 18/19 degrees. Didn’t help much from 16. I have it a bit more now but didn't put light on it.

Succeeded reducing stink but the stalling is issue. Maybe the float level needs to be raised a bit? This carb is a pain to remove and set internal side hung floats…….
 

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Stalling when you come to a stop can be caused by a slightly high float level, the fuel spills out the vent tube and momentarily floods the motor.

If I remember correctly back in the day with the side float bowls we used to put a piece of rubber tubing on the bowl vents letting it raise up higher and cut the top of the tubing off, essentially raising the bowl vents and preventing the stall in some cases.
 

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Discussion Starter · #3 ·
I found this also on another site:
A "quickie" test for too lean an idle is to snap the throttles open and closed real quick in a free rev (in park or neutral- no load). If the idle drops down low and then recovers it's too lean at idle. If it settles directly to the same idle speed without a dip, you're in the ballpark.

also:
Generally its too high a float level in the rear bowl, too low in the front bowl, and that plastic whistle tube that holley used to put in the bowls is a good help. Not sure if they are still using them. I think is a combination of both. Carb float choking and loss of vacuum. Do you have power brakes? Does the car have power brakes, if so unhook, plug vacuum and try?

and:
Stall or near stall when hard brakeing is too rich mixture or float level needs to be lowered.
Start with 1/8 inch from where you are now and in 1/8 steps till the problem is solved.
 

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Discussion Starter · #5 ·
OK, here is what I did so far. Lowered both front and rear floats and added a square rear anti slosh plastic channel to rear block. The stalling problem seem to fix It.

Changed IAB from .062” (@ 20.4%) to .066” (@ 18%) because all was adding up to rich with high floats and small IAB. This, I think, was causing engine to run on when shut down. I also had to open idle screws because of the leaner .066“ IAB’s. Throttle screw is still untouched so transition slot is still a square.

Raining so hopefully tomorrow will clear up.
 
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