What is the proper voltage ranges to know your FI is dialed in?

The reason I ask is my 88 started running down on power a week
ago............so I reattached the digitool, and am in  the
dark.............especially in regard to proper voltages for AFM, o2, and
pin 19............

I replaced the plugs and checked timing........all seems slightly better,
but my old plugs looked lean to me.

Adam P
81  Westy "The Brick "
70 Single Cab "Whitey"
74 Beetle "Ol Yeller"
73 Transporter (STILL at paint shop)
1988 Vanagon Wolfsburg
1976 Transporter (New CA bus)
1974 412 "Goldmember"
Used Vanagon Parts for sale (mostly aircooled)