750 aed stumble off idle/start

What size engine..??
What intake manifold..??
Is it an automatic..??
What is the rear gear ratio..???
It's a 340 30 over its a Victor 340, yes it's an automatic, 456 gear

So the timing marks have slipped back on the hub. Thats what they do. I your going to keep that balancer put a paint line across the front so you can keep track of how much it slips. Then find tdc and correct the marks. Even if you get a new dampner you still gotta check tdc. Did you take the play out of the accellerater pump linkage?

The line on the balancer for top dead center when it's at the mark the piston has started to move down just a tad. So your saying the balancer isn't good. Yes I messed with the accelerator pump linkage an after I changed the jets the car seems to idle an run an pull better threw the gears.