What is the lump on the injection pump

[Grasscutter234]

Hello would anyone know what the thing on the injection pump is and what it does iv never seen one before
It’s on a 1993 2.5 di manual
Closest I could get is possibly a ignition accelerator pump it has wires going to it and connects to a pivot on the side of the pump via small length of cable which looks like it mite move the throttle linkage when activated or while doing something else. Is it something to do with egr ? Cold starting ?
Thanks in advance boys and girls

[Chug]

Its a wax cold start device it moves the cam/timing in the pump.

[Grasscutter234]

Brilliant thank you I’ll search the forum again looking for more info thank you for telling me it is