engine backfire out exhaust

[kdogmcool]

ok so i finally got around to geting my new intake put on. i have put a new carb on top of that too. Its a chev 350 with a edelbrock performer EPS intake and a holley 570cfm street avenger carb. when i went to flash it up it started but had a popping out of the exhaust. it runs fine but it has a loud pop every 2-3 sec. what could cause this?

[jasonconnellee]

check your timing.

[kdogmcool]

It does it in every position i put the distributor in. I thought my plugs were fouled so in went new ones. still same thing. seems to run alright but a loud pop ot of the tail pipe. i dont want to let it run like that in fear of damaging somthing. So i set it at top dead center again same thing. cant figure it out.

[R Pope]

Mixed up plug wires, bad wire, bad plug??? All possible causes.

[thesals]

possibly vacuum leak, or leak at headers, sucking air in also.... sometimes a small leak in the exhaust system will suck air in and cause what sounds like a small backfire

[dhemi1]

Are you running lean?

-Chris