After Run Devices

[Pcarselle <pcarselle@worldnet.att.net>]

Brooks:

Both after-run systems are temperature controlled to start. The main fan
and auxiliary pump systems require reaching a certain WATER temperature
(usually "soaking" which occurs about 3 to 5 minutes after stopping the
car and assuming the engine had reached normal operating temperature.
The mere fact that the mechanically driven (timing belt) water pump has
stopped when the ignition is turned off, allows a very rapid heat
transfer from the engine block to the water and temp sector. Two things
are badly needed to prevent heat expansion damage (primaryly exhaust
valves and turbo):
1.- Water circulation from the bottom of the radiator (cooler zone)
2.- Air flow thru the radiator to remove the heat dissipated by the
water; thus the fan and auxiliary pump "tandem" work.
The duration of the after-run cycle varies somewhat depending on several
issues (variables)
1.- Battery, Fan (bearings, Electrical conexions to Fan, brushes etc..
2.- Cleanliness or obstruction of the radiator core...coolant formula,
auxiliary pump health, condition of hoses, internal block cleanliness
etc..
3.- Outside air temp
4.- Nature and intensity of the drive prior to killing ignition.(boost
!!!!)
In general the after-run process should last between 3 and 7 minutes as
determined by the coolante temp. at the thermoswitch. 
Injector cooling relates to preventing gasification of fuel prior to
entering or thru the injector body. (a form of "vapor lock").Keep in
mind the injectors are installed very close to the valves and run a very
high temperatures, in addition the seal integrity is assured by non
metal "O" rings, relatively resistant to heat.
The cooling function is initiated by the thermo switch which is mounted
at the rear of the engine and NOT in contact with the coolant but rather
with engine compartment temperature specially in the neighborhood of the
wastegate. 
> You wrote.....
"What I'm looking at to be the after run coolant pump, is a small
cylinder,
attached to the engine block near the rear of the engine, and attached
to the coolant hose right before it meets the radiator. Is this the
correct device? It's got a connector coming out of the same wire-line
that the injector blower is connected to. (that's why I'm assuming
they're related)"
Your description of the aux. coolant pump is correct. The connection of
the rubber hoses and respective clamps to the pump  are made to  very
britle PLASTIC extensions, which WILL !!!break with the smallest
twisting or turning.
HTH
Pablo