Is this a new vehicle to you?? No I had for 25 Yr. I been working on this car sent's I bought it. I built the engine 20 yr. ago it only has about 1000 miles on it. It been sitting for 15 yr. I started restoring it 5 yr. ago. I'm just a little rusty.
Or have you owned it for a while and this issue has just started to happens?? It started a coupe a month ago when I started driving it.
Define "below"TDC as you say?? The correct term is Before TDC, I know it was late. I just had it back words. standing at the front of the car the timing mark should be to the passenger side of the zero mark in order to be Before TDC. That where I was in front of the car and it is on the passenger side.
Bounce in the timing setting can be sloppy weights and/or loose springs in the distributor mechanism, it can be too much enfplay in the distributor shaft between the gear and the end of the housing, it can be a worn loose timing chain, or it can be a loose/slipped outer weight ring on the harmonic balancer.