Hey, i just swapped an '85 305 tpi into my '71 chevelle. I cut out all EGR and A/C from the harness, updated the ECM and everything else to run with a '165 ECM, and have a stock prom from an '86 305 tpi. I started it up, and it seems to idle alright, but as soon as i push the throttle, the engine is getting waayyyy too much gas, and it bogs down instantly and sometimes backfires. Before i put the engine in i put a penny in the regulator because i heard it was a good cheap mod. I just took the penny out and it seems to run even richer.

Can someone please help?

 

check the throttle position sensor. mine was bad and my car would start and then die unless i kept my foot on the gas but even then it would run for a few then bogg down and die. i replaced the tps and it ran fine.