Join Date: Mar 2002
Location: Austin, TX, USA
Re: 67 Camaro Back Firing Up Through Carb!!!
Backfire through the carb is a sure sign of a lean condition. Often it is caused by an accellerator pump problem making it difficult to transition from the idle slots to the main jets without a lean backfire. A manifold leak can cause it also. Unless the carb isn't quite setup, I'd suspect the vacuum leak first. You shouldn't have to tweak a new 600cfm carb that much to get it to run right. Sounds like you've got a serious issue that goes beyond the carb.
Verify the firing order is 22.214.171.124.126.96.36.199 and check for carbon tracks on the inside of the distributor cap that could be causing cross-fire.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI