I'm anxiously awaiting "Special Delivery" of a new ICV that I bought from E-bay over the weekend. I'm hoping to find that the internal return spring is a good deal stronger than the one in my old unit.
I spent ages cleaning the thing out, only to have a
worsening of my high revving symptoms. I have a speculative theory that as the spring gets weaker with time/temperature/gunk or whatever, it is insufficiently strong to return the valve to a shut position when the ECU/solenoid 'tells' it to. Cleaning the valve area out will tend to 'open' it more than when it was thoroughly gunked up, maybe? The solenoid can only push it further open, after all. The airflow through the valve (on my x20xev engine at least) is in the direction that will tend to push/hold it open if this spring isn't 'man enough'.
Anyone thought of using an electric toothbrush for throttle-body/ICV cleaning etc? I wondered whether it might be rather 'fit for purpose' the other night whilst "Sonicaring" my teeth.

Edit 11.30: Well it's arrived. First impressions are that it's got a significantly stronger spring in it. But also, I've spotted something I hadn't noticed on the other one (maybe 'cos it's not there on that one): There seem to be a couple of 'bypass' drillings that go from the 'in' side of the valve to the 'out' side (via the part where the spring sits), parallel to, and behind the actual valve passage...The new valve has zero in the way of identifying part numers, so presumably not a genuine part, but I only paid £40 for it, so no surprises there. I wonder if these extra drillings are the difference between the old part number and the one with the fabled X on the end??
Will fit at lunchtime; then, if problem solved, dissect the old one...