any sd33 mz pump or old ford york pump gurgues out there?

[zen]

cos if there are could you explain to me why they are prone to "pulsing" on light throttle,and even offer a cure??
its when keeping a steady ususally sub 40mph very light foot(flat road)type of speed,starts to get a pulsing,which if not corrected(more or less throttle)will result in it causing the transmission to "clatter",as if its realy worn and bouncing on the worn uj's diffs etc)(WHICH IT ISN'T,cos i have replaced most of it..)
been told its very common on n/a sd33 patrols by a man who has owned lots..also occurs often on the old 6pot ford york engines(that frequent his farm tractors)

thinking its the pump diaphram pulsing on the vacum thats causing this,but why?cure?make a plemun chamber?bigger/smaller air lines to pump?knackered spring/diapram etc?

your thoughts welcome

[RMP&O]

I have noticed the same thing on my 83 MQ...which is a NA SD33. I thought it was wear in my u-joints but they sure do seem tight upon inspection.

I am not to worried about it right now though because my MQ only gets driven on weekends to go off-roading. And sooner or later my motor will get torn down, ie new pistons and all that jazz when turbo is fitted. At same time I think I will be tossing in a new injection pump.

[zen]

ah so it is common,but why does it do it????

[zen]

oh been told its down to leaky inlet gasket..(or leaky pipes)