Ok...So, I have a 1976 Ford f-100 with a 360. (thought it was a 390, but it's a 360) When I start it up cold, it backfires through the carb. I thought it was a timing issue, so I had a mechanic check the timing while it was in the shop getting new exhaust. As I thought, the timing was set back to 3 and is supposed to be between 6 & 8. When he put it up to 8, it idled fine but would backfire really bad through the carb. He said he "thinks" I might have a bad timing chain. He is going to leave it set at 3 so it will run ok. My question is this...How can I be sure it's the timing chain and not something else?...stuck valve, bad carb, worn lobe on the cam, plugs not gapped right, firing order off, distributor off one notch? Anything? Any ideas? Anyone run into a problem like this? Any help would be greatly appreciated. Thanks

 

Backfiring on a cold start often means the choke is not closed at startup. Check that out.

 

FMC is right sounds like ur choke isnt closed