Reading through the Helm's manual (pages 4-44 to 6-6), there's really a ton of other stuff that can go wrong with the vtec system. Among other things, this could all affect our vtec systems:
- IMRC actuator
- vtec oil pressure
- rocker arm
- solenoid valve
- actuator cable

So why all the focus on only whether the IMRC actuator moves?

 

Maybe it's the easiest out of all of those things to verify
by one simple visual/audible check.

And not everyone has a Helms service manual, coupled with a technical background, or courage to take the engine cover off and open up the Intake Manifold.

But you're right to be curious because the first production batch from april '00 to approx. aug'00 had a limited problem and I think "JZ" was the one who spoke about it while we were still on the motherland site Acura-TL.com, if my memory serves me correct.
And Tom2 was somehow in the mix of this as well.

Leme see if ATL.com still has the thread...