The issue is with vacuum. You have too much of it.

There must be an adjustment on the 210 to reduce vacuum to the modulator. You'll need a vacuum gauge to determine where you are at the moment and you'll want to drop it by about 2" and take it for a test. All vacuum adjustments need to be done in small increments and they can't be done without a gauge.

Brian,

Thanks - I will get hold of a guage. Have you any idea of the name of a good brand and where I might get it from?

I will have to get it out of the US as there are very few places here in Australia that would stock such a thing.

Also, as for the adjustment, is it done down by the transmission itself or up at the IP?

I can see a black hard vacuum tube coming down from the engine bay going into the right hand side of the transmission into an orange plastic gizmo (modulator?) with a white plastic cap at the top.

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1995 E300 Diesel