When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a 1979 L82. New 2701 Edelbrock intake manifold, 600 CFM Holley street warrior, new Summit distributor, Accel plugs and wires, long tube headers to side exit with Flowmaster FX mufflers. Not side pipes. 1 inch carb spacer, Locar throttle cable. When I give it throttle it back fires through the carb. Set timing from 4-12 and still does it. If I have deleted all the emissions should I get the vacuum advance from the intake and not carb? Or any advice would be appreciated. She back fired thru carb
I can see right now that you allow #5 and #7 plug-wires to run parallel / together.
Due to the firing order of older GM V8s, number 5 and number 7 wires should always be separated in the looms. One on each end of the loom.
Those two can and will foul each other. It's known as Cross-Fire-Induction.
Is that the reason for the carb flash? Probably not. Usually it's a lean condition, sometimes an Intake valve is still open at a slow crank.
Mine does it occasionally. No worries.
And your timing settings is "smog-numbers". Bump up.
Last edited by HeadsU.P.; Nov 6, 2023 at 05:07 PM.
From: At my Bar drinking and wrenching in Lafayette Colorado
You have a lean condition. Richen it up and get some timing into it. You also might want to pull that 1" spacer out of there - it's not doing you any good on an otherwise stock engine and, along with the headers, is further aggravating the lean tip-in you're seeing, causing the backfire.
Lars
Back fire thru carb
