Holley 80457-2 stumble

crackedback said

Make darn sure the accelerator pump is shooting as soon as throttle is pulled. Any delay there will cause a lean spike.

This is another reason I'm a BIG fan of A/F meters so you can see what's happening in actual driving situations. Saves time in the end. No guessing and throwing parts at it. Make it portable and all you need is a bung in the exhaust headpipe/collector. You can do a lot with an A/F meter and vacuum gauge.

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I messed with the truck today, and found an issue.
For some reason, the gasket on top of the pump discharge nozzle was leaking slightly at idle????
I replaced the gasket and it helped the throttle response slightly.
To me the pump shot is weak, It does not shoot hard as soon as the throttle is moved.
Everything in the acceralotor pump seems in spec, it just seems to be a weak shot of fuel.
I am out of ideas to check unless for some reason pump diaphragm in the rebuild kit I used is defective.
I bought this carb used cheap, maybe it had issues from day one?