I live in Spain and run a small garage come mobile mechanic business here for many years, but have been sidelined due to health issues.
I own a 1994 80, same engine. I removed the Automatic Cold Start Device many years ago, in our climate it hardly affects idle speed, with it removed and the removal point blanked off it is job done. I have read a few times about a small 'tang' that operates the timing can break off and leave the pumps damaged, given some of the isolated places I visit alone decided I would rely on the glow plugs to get the engine started if need be, the truth is being a direct injection engine they are not really needed. Although they may help with cold running emissions? The pump is very common on many diesel engines, the blanking plate will be sold to you (with gasket) for a few euros from any diesel shop, there may be one lying in a parts bin of old pumps, drive in and point to the area you wish to blank off and you can do it when you return home plate in hand. I seem to recall that one or two of the original ACSD screws might be too long or short? I used other screws from the another part of the ACSD assembly, forgive my poor memory if I am wrong. As the ITV emissions test is only carried out with a hot engine the removal of the ACSD has no effect on emission output.
I would do the following, get the engine to temperature by driving the vehicle, idling will take ages, so a good run perhaps ten miles? With the throttle disconnect from the pump reduce the idle speed to 750 rpm, if is seems (sounds) fast your revolution counter could be off, see how it feels when you select D, or R, I seem to recall your car is automatic, or have I gone adrift somewhere.....it happens. If gear engagement seems comfortable, the next step is park the car facing uphill and with it in neutral check what your revolution counter shows, write it down, next turn the car around and do the same again in neutral and check the revolutions. If they are different then it is most likely there is a small spring broken in the pump, if I remember correctly it is on/near the governor assembly?
Mine started doing this a few weeks or a couple of months after purchase, I investigated further and it is one of the jobs that can be done another day, I never got around to it, and up until nearly two years ago the car has done over 100,000 miles like this and does not bother me at all, even off road with the front of the car high in the air the slow idle does not give me any issues.
In case you or anyone else was wondering, I even bypassed the fuel supply assembly to confirm it was not the filter in the tank, or the main screw on filter, or the often overlooked filter under the plunger assembly in the pump, it is easy to do this, just drive around an area away from the road with a gallon of diesel tied to the roof or roof rack on mine, pipe to pump, bonnet on safety catch..........yeh I know!
See if that helps, but remember to check all the base setting on the pump as described by other members first.
Regards
Dave