94 suburban timing issue

[dheavychevy38]

Ok my dad gave my brother our old suburban it's a 94 1/2 ton 4x4 with a 5.7 tbi. The first motor bent the crank and ruined the dizzy. So new motor and dizzy all good. It's like 2 years later and now the thing won't stay timed. It goes almost 15 degrees out when it wants to. What do you guys think new dizzy again or ecm issue ?

 

[longbedder]

Are you disconnecting the timing advance wire when you're checking/setting the base timing?

 

[dheavychevy38]

Yep thats when it bounces. it surges like when you have the a/c on but it's not on. Check and installed a new dizzy to day same thing.

 

[bigblock72]

What are you setting the timing at? I'm a little confused as to what the concern is.