Helping a friend with a 427/425 that we put a MSD dist and spark box in. The problem is according to the MSD graph, the mech. advance starts at 0 rpm and is about 4 degrees at 1,000rpm. So when setting the timing at 850, there's apparently already a little mech. advance in.OK now when you blip the throttle, you get more mech. advance which in turn wants to cause the engine speed to increase which won't let the mech. go back to where it was. Therefore the idle is now up around 1100 and will slowly (~30-40 seconds) come back to 850. All of the MSD springs show this same amount of advance at 1,000 rpm. Any ideas??? [sm=dontgetit.gif]

Will post in C2 section also.

 

"Old school" tells me to set 5 to 7 degreesadvance at idle. After the timing setup, tune the idle screw down to desired rpm. From there, I "tune by ear", adjusting carb and tweekin' the dist.I still use the ol' dist. with adjustable points that ya can tune while engine is runnin'. ( usin' an allen wrench )