Free time and bored, so did some idle/vacuum readings now that I’ve adjusted everything by the book and the car is running excellent. For others reference?
I am running a USA 1988 HE V12 A/T with ignition timing at 22° BTDC (@3000 rpm) with 92 US octane fuel. (OEM is 18° with 87 US octane)
Cold - vacuum 14.5inHg at 900rpm
160F - vacuum 16.5 at 800rpm
Warm (180F) - vacuum 17 at 750RPM
PCV plugged - vacuum 17 at 600 rpm
Car in D or R (closed loop) - vacuum 15.5 at 700 rpm
Also, checked exhaust for misfire, slight intermittent both banks in open loop, perfect in closed loop. So surprisingly I get a smoother idle in closed loop, although I do have the ECU a tad rich (2.0V, 1.95V).