200TDI revving on startup

Hello people,
Fitted a 200tdi into my Lightweight, and its all ok apart from the engine revs like mad when starting from cold. It isnt a self ignition/burning oil problem, as I can switch it off when its revving, if it is left to rev, after a second or two it settles down and is ok. When starting from warm, or even just a minute after the initial start, it starts perfectly. I could really use some good suggestions please.
By the way, it appears the injector pump has been "adjusted" in the past, as there are no seals fitted to it.

Many thanks

Has the engine been off roaded?
If so its worth popping the top of the pump off, 4 x screws and removing the diaphragm to check the fuel pins isnt seizing from water ingress, sounds scary but is a 2 minute job.
Stupid design.
Does it smoke much when you drive it?

This article might help
View attachment Bosch VE pump Thermo Guard_Tdi_Tuning_Rev.2.pdf

Lynall, the landy has just been rebuilt and is not on the road yet, but it doesn't really smoke too much. I will take a look at that, thanks.
Blackburn, thanks for that info, I've saved it and will be taking a look ASAP.