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There is a gain in efficiency for Stratified Fuel Injection(SFI or FSI depending on whose doing it ^_^). It allows you to cool the the air in the chamber. The idea is you have like a water sprinkler system on your lawn that clicks back once its reaches its full travel range? With gassers they are looking at lots of injections(most are talking 7 or more).
The problem with injecting all at once is some of the fuel might ignite before it all gets in, so in that sense diesels also have pre-ignition(it happens before you want it to(but its not engine destroying catastrophic like gassers). stratified injection lets you cool the cylinder with several small squirts so when you go to dump most of the fuel in the last 2-3 injections it all gets in before it ignites(otherwise you spray fuel in 02 empty areas of the cylinder and they don't burn). It also allows for a much, much more homogenous burn mixture because the outset pulses are already completely dissipated around the cylinder when the ignition event happens.
If pulsing is the same as stratified injection there are efficiency gains to be had. I do not believe it influeces emissions. In gas engines it does but thats because to do this requires the use of GDI, which is the prime mover in emissions reductions, not stratification.
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