I converted My TBI to Carb Holley S/A 770 and used the Vac advance dist. from Proform. When I put the timing light on the tab (with the vac. line pulled) the timing line will jump from 12* to 6* and back and forth. I used my light on another car and it was fine. What would cause this??? Could I have a defective module????


Thanks
Brian Felts

 

does it search for idle rpm? is the mechanical advance coming in? bad distributor? air gap on stator wrong?

 

No it idles fine and there is no change when It does it. It will do it at idle and when I put a little RPM to it. Its all new thats the problem I just can't figure it out. I did use the light on another car and it worked fine there. Think about it and see what you can come up with.


Thanks
Brian