Just a quickie to say that my mate has built a 'plug & play' box that simply slips inline with the RC valve servo and actually got them working again.
We're still working on refining the electronics, but it worked for three laps then blew a fuse!
The plan is to make a box that will be isolated from the PGM2, 3 or 4, which will then bring the valves back from the dead. the plan is to measure rpm and throttle position and then open the valve a preset amount. I just tell him the numbers and give him the electronic headache
He says that once we've got it basically set to open at a set rpm blah blah blah, it'll then be quite easy to modify initial opening and fully open parameters either by rpm or throttle position.
I'll keep you informed