So I noticed this the other day, when I was driving with my top on and was actually able to hear something other than wind! It seems my engine is pinging pretty bad but only in very specific circumstances. The engine must be completely warmed up to temp, at HWY speeds (above 50mph, so 4th or 5th gear), and only at mid throttle. It seems that under really light or full throttle it doesn't do it (of course its still loud as crap and hard to tell
This is what I do know:
Timing is set right at 9*BTDC
Both vacuum and mechanical advances are working as specified in the FSM.
So I don't think its a timing issue.
New plugs, wires, cap, rotor.
Choke is working properly
Vacuum powered air intake doors are functioning correctly (i just fixed them)
stock carb that otherwise runs great!
Stepper motors appear to be functioning as far as I can tell.
Any idea what would cause this problem or how to diagnose it from here??? I have no problems under any type of acceleration (light, moderate, or heavy) from slower speeds in any gear or RPM, I find this really odd! I may be trying the nutter bypass in the next few days when I get some time, don't know if this will help or hurt.