I'm not sure if Mk 1.... All I do know is that with TPS connected / disconnected the PV does not move from LO position, only when revving between 2000 - 3000 rpms does it move to HI and past approx 3000 down to LO again. And I agree with Stephan that it most likely setup incorrectly as I can hear a buzzing sound from PV when ign and switch on, guess its trying to close an already closed valve!