That is why you need to disconnect the timing connector, adjust the timing to spec(4 degrees on this aplication), reconnectt he connector and let the ecm take over. I really strongly urge you to go buy a cheap timing light, watch some youtube video's on how to set timing and do it yourself. There are tons of folks here that will help you. Shine the timing light at the harmonic balancer timing mark on the driver's side of the engine. Read the number on the timing plate adjacent to the timing mark on the balancer.
It is backfiring through the exhaust and will not start. Pulled the valve covers to make sure a spring hadn't. As a sbc fan and end user, i no longer check the idle timing! Sbc's sweet spot is 36 deg btdc with vacuum disconnected and mechanical all in by 3500 rpm. So for 36* total timing you would mark your damper at 2. 51 ahead of the timing mark. Then rev the motor slowly until you have full mechanical advance. I came across a timing light at a yardsale so i checked the timing on my mid 70's 454, the harmonic balancer timing mark wasn't on the tab on the timing cover! I know how to set the timing properly, i'm just looking for where. Setting timing for total only with no regard to base timing is a racers trick that's just fine for a round round or strip race car motor that is generally at or above where total timing is. My initial timing was set at 15* and total around 44. The total sounded like a lot but i was not getting any detention. The issue i found was my vacuum advance was connected to. So basically the initial timing of your 454 will depend alot on how much mechanical timing your particular distributor adds.
454 timing
The total sounded like a lot but i was not getting any detention. The issue i found was my vacuum advance was connected to. So basically the initial timing of your 454 will depend alot on how much mechanical timing your particular distributor adds.
