Hi,

I do not recommend using more than nine volts from a dry cell battery for operational simulation for observation.
I have my reasons and you are bringing up one of them.
A car’s wet cell battery has unlimited capacity to pump excessive current into the windings instantaneously.
It causes things to slam!
There’s a limit set by the ECU’s type of transistor and resistor capacity going to ground.
The transistor circuitry turns on and off very quickly and those pluses limit the amount of vane opening towards a spring.
There is a repetitive stopping point for the spring and a half turn motor rotation.
On the original IAC’s, before EZK, there was three pins and the polarity or the current was turned on or off to modulate the opening of the vane to the center pin.
This moved the motor back and forth without a finite low flow stopping point.

The spring design was put in as safety measure for engine control of lowering RPMs, fast, in case of a power loss Signal from only the ECU.
This has been born out on other car manufacturers that drive by wire for their issues at stop lights.

I have never held the current on the terminals, for any length of time, as it has no purpose to prove except to jam it one way or the other.
This thing has to move freely between extremes.

For all I know there could be a “thermal” cutout operating inside the IAC. This could cause the shutdown and resetting that you are describing.

I believe the Trev man from Canada is right that if the IAC or the AMM are perfectly fine you are still running too lean.
Any extra air behind the AMM is detrimental to the computers knowledge of what is going on.
It may mot be able to throw enough fuel at it if the fuel volume is low due to bad pumps, filters, FPR and so on.
The intake manifolds can get finicky with old gaskets or warpage on extreme age cases. It comes down to “What the heck! I’ll do it.”
There just some things you have got to leave up on the troubleshooting table, when it’s bouncing around like it is in the video.

The timing is close or it would not hit and run that slow without popping in the intake more often.
A quick check of putting the crankshaft up on zero and the rotor under number one plug wire is easy to do.
Then, you take the screw out of the plastic cover on the back top side do you can peel it back.
You want to look for the notch and dot to be in line up there within one tooth only.
If it’s a little off a tensioner adjustment might fix it.

This is the Simple stuff on these cars but only if you take a little time or patience and be stirring them together!

Phil