vaccum advance ?

[Blazin'4x4]

Im still fighting my ignition problems and a new one has arisen.

Why would my timing retard when I use the accelerator? Isnt it supposed to advace past the 9 degrees timing I have it set to? It drops down to almost 0 with the throttle open and back up to 9 at idle.

Quick specs:
1972 350
Hei
Carberated
New advance, new springs work great.

 

[dyeager535]

Sounds like your mechanical advance isn't working.

 

[4X4HIGH]

Is your vacuum advanced hooked up to ported vacuum or manifold vacuum?

 

[Blazin'4x4]

ported on the carb. also the advance unit is brand new

 

[onetonbb74]

do you have an aftermarket hei? Mine uses and adjustable mechanical advance that required a 3/32 allen wrench to adjust thru the vaccumm advance hole.