Can someone explain to me how the VVT works on a RS197/200?

[HillclimbRS200]

The solenoid valve seems to be an on/off switch, same as the 172/182. Can someone explain how it can provide proportional control in the later cars? Also, how would the voltage at the solenoid and the cam position sensor be expected to vary with rpm and throttle position?
Thanks

 

[pepinosport]

maybe it works with pulses? IDK, but more pulses more duty cycle, so you sort of control the oil flow into the dephaser. just brainfarting here

 

[S24nrc]

Theyre PWM based vs the older cars having a on/off style VVT.

 

[HillclimbRS200]

Thank you for the information. I no longer have easy access to an oscilloscope. Does anyone know if an iCarsoft scanner can display the pulse width or does it not acquire data at a sufficiently high frequency? I think that it must be very similar to measuring injector pulse width.

 

[Seriosha]

Many DMM's have functions for measuring duty cycles! Those should be relatively easy to come by (compared to an oscilloscope)

 

[HillclimbRS200]

Thanks everyone for your help. I have now checked the signal to the VVT solenoid: there isn’t one. Time for professional help I think.