Off-idle hesitation and backfire

[77-4speed]

Hello again all,

Well it's nice weather and I've got the 77 out on the road more and more. I have noticed a problem though. I've got an edelbrock 600cfm egr carb with electronic choke, and I'll usually let the car warm up for quite a while before I drive. Anyhow, once I'm driving, any time that I hit the gas, the car stumbles and often "back-fires" through the carb. I have the timing set to 36 degrees, all in by 3000 rpm (I had to use the lightest springs in the kit).

The carb is less than a year old so I can pretty much rule out the accelerator pump. Any ideas?

Thanks everybody.

Russ

 

[1BAD80]

The accelerator pump may be good but it is not adjusted correctly.
A lean condition cause's a backfire thru the carb which takes you back to the accelerator pump. Here's Edelbrocks tech site that tells how to adjust the metering rod's.
http://www.edelbrock.com/automotive/index.html

 

[77-4speed]

Thanks 1bad80! I'm going to go have a look through the Edelbrock site. I didn't know if it was a lean condition or rich condition that caused the backfire through the carb. Is is also possible that I have too much timing coming in early with the very soft springs in the distributor?

Thanks,

Russ

 

[1BAD80]

Very soft springs in the distributor will give spark knock coming in to fast. I still belive its to lean, to rich on the pump will be boggy or slugish.