Quadrajet stumbles-fuel?

[78Blazer]

Hi all,

I have a 1978 Chevy blazer with the following carb on it. Quadrajet # 7042910 QH. Here is the problem, after the motor gets to running temp. under load if I mash down on the pedal the motor goes dead/stalls. In order to prevent it from not dieing all together. I have to let up on the pedal, hit the pedal again and then after a 10-20 second delay the motor gets up and going.
After it gets up and going it still seems to lack power/ fuel for another 20-30 seconds.
I thought maybe a fuel pump problem, so I replaced it. No big deal the motor was leaking oil there anyhow.
This is my first quadrajet, and I have no idea on the condition as I just bought this blazer.  timing looks to be at 8-10 degrees, and the timing chain just got replaced he showed me the receipt from the shop.
Thanks all for any ideas..

[Shark Racer]

Do the secondary air-valves have proper tension and a functioning choke pull-off? Sounds like you're flooding it to me, and the first thing that comes to mind is someone tried to "speed up" the secondaries without knowing what they're doing.

[Cliff Ruggles]

Secondary cam cracked, broken or missing?  Secondary shaft spring worn out?......Cliff