I'll bite. Even though I'm a total newbie, I have learned a bit from reading.
In the diesel, the intake stroke pulls in air only. The fuel burst(s)is injected toward the top of the compression stroke. The injector meters the fuel based on various inputs (I'm guessing TPS, engine load, RPM, etc. ). The ignition of the compressed air/fuel is due to the heating of the air under compression. Since the combustion isn't from a spark, we don't have to worry about the optimal 14/1 air/fuel ratio to produce optimal ignition/burn.
How'd I do?
David