TAN timing advance wire on Computer and stumble...

[Supersix]

Here is my situation I am getting a stumble at idle ..if I disconnect the tan wire on the computer the stumble stops...My whole ignition is new..all with the recommended stuff everyone uses here...Has anyone encountered same type of proble? What was the repair?....Thank you for your help..Rob

 

[KBowman]

Need more info. When did this start doing this ? have you added or changed anything recently? and if so what and before or after it startied doing it? Not knowing what you have checked so far I would start with the basics.
How much fuel pressure do you have? When you give it some throttle does the fuel pressure rise?
Where is your base timing (with the wire unplugged)
Does it do it when the motor is hot and cold?