Hi Matt

Thanks for your post. Regarding the control of the RC valve by a PGMIII or PGMIV unit, are there stages to it's opening, or is it simply open or closed? Just by watching it while free revving the engine, it appears to be either open or closed, so I thought there would be some gains to be made with a valve which opens in multiple stages vs, engine speed, and TPS.

As for the air solenoids, this is something which still mystifies me! Can someone explain exactly was it is these things do? Are they a vacuum meter so the computer has another way of gauging engine load?

Cheers
Tom