Author Topic: Quadrajet stumbles-fuel?  (Read 1328 times)

Offline 78Blazer

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Quadrajet stumbles-fuel?
« on: December 02, 2012, 10:03:50 AM »
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..

Offline Shark Racer

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Re: Quadrajet stumbles-fuel?
« Reply #1 on: December 02, 2012, 09:14:56 PM »
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.

Offline Cliff Ruggles

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Re: Quadrajet stumbles-fuel?
« Reply #2 on: December 04, 2012, 03:32:08 AM »
Secondary cam cracked, broken or missing?  Secondary shaft spring worn out?......Cliff