I'm a little confused;
if you shut it off while the idle is high, and then immediately restart it; what happens?
According to post #1
Is this with a carb?
Do you have variable duration lifters?
I don't see the tach running in reverse, I see it dropping to zero immediately after the blip, as if the ignition was shut off, and immediately it recovers. And the engine seems to be doing the same thing; so my guess is that the tach is actually telling the truth?
The AF gauge seems to be echoing as the numbers go very very lean during the stumble.
Ima thinking you have multiple issues;
1) does the cold engine idle rich,then over time gets air somewhere other than the primaries, which increases the idle speed
2) the engine cuts out on tip-in, and
3) I can't figure out the electrical cutout
