do these VVT'S really make a difference, I mean, can one really notice the alfa with one vs without one?
Definitely, particularly in the mid to upper RPM band, though there is a increase in torque down low too, so it's kind of an 'all round' enhancement.
it seemed to me that the VVT triggered to high in the gas pedal travel, more that I think I drive my car (seldom past 4K RPM) hence wanting to have a light to tell me exactly when the AAV was triggering.
If the is TPS set properly, 56+ degrees deflection of the TPS, regardless of the RPM at the current time. (RPM has little to nothing to do with it in other words. EG: pulling away from a dead stop with more than 1/2 a pedal is enough to kick it. So will rapping the throttle while sitting there in neutral, or even with the key on and the engine off)
I did a LED with resistor on mine for a period of time by connecting to the + side of the solinoid harness and taking the other side to ground.
With the resisitor in-circut, the 'short' is so small that it doesn't effect the operation of the solinoid proper.
BTW, papajam discovered that the harness puts around
8 volts to the solinoid,
not 12 like one would expect. This would have great bearing on the type of resistor used in an LED setup.
As to 'needing' a light to see when it's on, kinda useless actually as you can indeed feel he difference when it's not on vs if it is, and if it tests as functional per the given means of doing said tests, then it's working the way it should and having an indicator light ends up being more so much fluff rather than anything useful.
A periodic check of function, like during oil changes or something, is more than adiquate to let you know things are going right.
If the idea behind adding a light is to try and get better economy by keeping the engine out of the VVT, then adding an econobox to to the private car collection would be much more sensible than adding a light to the VVT so one could avoid using it.
Elio Comello said:
There is very little out there that discribes in detail the functional logic map and any "crosstalk" of info between the Injection and the Ignition ECU's.
I fully agree with that. Knowing exactly what the magic (or logic

) behind it is would be great.
Perhaps a VW or Volvo mechanic from back in that era would have an idea. (presuming they got more information in general than Alfa mechs)