What's this relay do

[onc onc]

Hi all, can anyone tell me what the relay in the black box on the bulkhead in engine bay is for. Van is a 1.9 dg petrol engine. I been having a few cutting out and stalling problem lately. I have fitted a new coil and a carb rebuild kit has been fitted. Next up is probably fuel pump. But could this relay be causing a problem. I have no idea what this does. Thanks

[Aidan]

heat to the inlet manifold and choke unit, switched by temp switch in waterpipe

[onc onc]

Thanks Aidan, do you think this could be part of the problem with cutting out, stalling and cold starting problem. Thanks again.

[Aidan]

cold start procedure - 1.9 2e3 carb engine

press accelerator to full and release (do this twice in really really cold weather) this puts the choke on and a squirt of fuel into carb to aid start, the second one gives an extra pump of fuel, don't go mad and do it ten times
start engine, it should start and idle and as it warms up the choke is automatically disengaged as the coolant heats up even if the choke heater isn't working but it may be a bit rich a bit longer
if you leave it idling before driving off it will start to rev a bit high unless you blip the throttle after a couple of mins on a cold morning generally
the manifold heater helps prevent icing of fuel as it is drawn in, but really it has to be very cold and your fuel full of water for it to be a problem unlikely here and now in the UK

you don't describe your problem(s) much so difficult to know if this is related

warm it should just start with no aid

[kevtherev]

Removal of the intake duct will show you if the choke has set after depressing the accelerator.
The fast idle (cold) will also set at this time
Both the choke and the fast idle take around 6-8 mins to fully come off.

Be sure the choke flap is operating correctly.
It should open fully
On a cold engine it should be opening smoothly by the choke pull down unit as the accelerator is pressed (engine running)
The choke flap gap should be set correctly on the pull down unit.(Haynes)
The choke and fast idle are fully adjustable.

Cold engine stalling is usually a mixture issue due to the choke operation imo