Looking at the throttlel plate as you rev up the engine can you see the throttle plate move. .And if it is not opening the plate you need to look at the potentiometer on the side of it .This opens the throttle plate .Some you can replace ,on my m103 you can replace it ..Another one is on the throttle body assembley the cable that comes from foot pedal thats fitted to the bottom side of throttle actuator .On it, its got a small micro switch ,some have two.Try them see if the click. If so they are working.