Carb problems

[jaredmajor]

i have a 650cfm mechanical secondaries holly carb. Off idle, cruising or anything if i step on it hard it cuts out for a second, but once i get past that point and floor it, no problems. Is it loading up or what? any ideas?

 

[eagle mark]

Accelerator pump adjustment or replacement.

 

[jaredmajor]

Cool, should i replace it, i think i have it adjusted right, according to a holley tuning book. What about replacing it, i noticed there are 30cc and 50cc, which would be better for gas millage, or does it matter?

 

[theperfectgarage]

Could be the pump shot, the 50cc will use a bit more fuel, but I would'nt sweat that.
Could also be your secondarys opening to fast.

 

[jaredmajor]

I'm pretty shure it's not the secondaries, it's right off idle, i don't know.

 

[theperfectgarage]

I agree, I must have missed the part of " just Off idle ".
Then i'ts back to the pump shot. Does your model carb use the different colored nylon pump cams on the throttle shaft ? How about your idle air fuel mixture screws ? Maybe too lean there ? How about vacuum leaks, have you checked for that?

 

[jaredmajor]

it's a 4150, i dont know about the colored cams. I set the idle air mixture in colorado(elevation) and it acted the same there. I am in anchorage AK now and at see level. I don't think the idle air mixture is it. It's acted the same at both low and high elevations and i had it dialed right it. As for vacuum leaks, none, i only have two vacuum lines. I am almost positive now it's the pump. I will check with napa and see if they have a little kit, then see what happens.