as my earlier post stated I would like to know what the 2 vaccum units do on my pump unit. I have posted some pics to maybe make it more clear.My suspicion is that maybe during overrun the throttle is allowed to back off further than idle speed so giving more engine braking as one of the units when positivly pressurised acts as a throttle arm stop.The other unit speeds up the idle under negative pressure.I think there is an air valve in the oil pump which is run off the back of the alternator(to feed the turbo) which allows the air pressure or vaccum (I don't know which) to be shut off when the oil pressure is high as the valve is open when the engine is stopped. There is a large tube that I dont know where it was fitted feeding the valve and a small diameter pipe exiting the valve going to one of the vaccum units(I dont know which as the tube was cut).There is nowhere on the engine or the air filter box that the large tube can fit.There is a small connector on the airbox that takes one vaccum tube and one on the inlet manifold that would appear to connect to the turbo unit on the pump.Any Ideas?
