Backfire over 3000 rpm?

[joesregalproject]

I have a bone stock 3.8 N/A Buick V6 in my Regal and today I pulled it outside for a few friends to see and as I was revving the engine in park, it was backfiring over 3000 RPM. It wasn't warmed up but even after a minute or maybe two, it still backfired when over 3000 RPM. Any ideas?

 

[Evan11]

I have a bone stock 3.8 N/A Buick V6 in my Regal and today I pulled it outside for a few friends to see and as I was revving the engine in park, it was backfiring over 3000 RPM. It wasn't warmed up but even after a minute or maybe two, it still backfired when over 3000 RPM. Any ideas?

plugs, wires, or timing likely

 

[pontiacgp]

ignition module

 

[olds307 and 403]

Over advanced ignition timing will definitely do it.