I've had a few vhicles with Perkins and the cold start device in the inlet manifold.
The way it's supposed to work is:-
During normal running, the small reservoir above the inlet manifold fills up with diesel from the back leakage tubes connected to the tops of the injectors. The cold start device contains a heater coil, a bimetal strip, and a little valve. When the device gets 12V, the coil heats up and bends the bimetal strip. This opens the little valve, and lets diesel drip onto the hot coil. After ten seconds the coil is hot enough to ignite the diesel. Then the engine is cranked, and this sucks the burning mixture (by now a right little bonfire) into the cylinders, igniting the normal injected diesel.
This system is a bit agricultural, but seems to work pretty well.
You could do the following checks:-
Check that you get 12V on the device when the key is at "cold Start".
Check there is fuel in the reservoir.
Pull off the air duct from the inlet manifold. Turn the key to "cold start". After ten seconds the fuel should ignite to a good flame, not just fizzle and smoke.
Then crank the engine. The flame should swell and you'll see it get sucked into the engine, and it should start.
Some problems that can occur:-
The reservoir leaks, or doesn't fill up with fuel. Or has been standing for a long time.
The heater coil can become bent, so it obstructs the bimetal strip, or doesn't heat up properly. It should get red hot.
You try to start the engine too soon. The air rushing past will cool the coil, so the diesel won't ignite.
I always have a spare cold start device handy.
Hope this helps.
Colin
Commer PB Jennings