Alright I got a race coming up and I need my carb tuned perfectly. It's Holley 650. When I'm driving the car it runs smoothly, until I romp on it, when it's floored it'll pull hard for a second then cut out and fall on its face. I'm pretty sure this means it's running lean but I'm not 100% sure.

 

Sounds like you may be having some fuel trouble. What type pump are you running?

 

It's just a stock replacement I got from Advance auto parts

Oh and it's mechanical

 

That pump should work fine for you. How long have you had the carb on the car? It may have a passage clogged somewhere.

 

Whens the last time you replaced youre fuel filter?

 

well the car worked fine when I first bought it. Thats when it was stock. After the engine was rebuilt it's never really ran right.

 

Check your float levels, they might be a bit too low.

 

If you don't have a lot of time for experimenting and tuning, maybe a shop with a chassis dyno is your best bet.

 

Well I've been driving around it seems like it stumbles when the secondaries open. Maybe I need larger jets for the secondaries???

 

Check to see if the pump arm for the secondaries doesn't have any play. It might not be getting a squirt of fuel right when the secondaries open.

 

Just checked the pump arm, there is a little bit of play. I think a little bit would be normal but I dont know. What do you think I should do to tighten it up?

 

If there's play when the throttle is closed, it's wrong. It should move the pump instantly. When the throttle is wide open, you should be able to move the lever about .015" more before bottoming out the lever to the pump.