Recently rebuilt 2nd gen suddenly won't start - where to begin?

[MmSadda]

Okay, here's the deal -

I'm driving an S4 (87) n/a, stock for all practical purposes, got about 25k miles on a rebuilt engine, and at the same time got new fuel pump, new injectors, new ignition coils, etc.

I drove the car two days ago, and it ran 100% normal. Tried to start it today, and it'll sit there and crank and crank but won't actually fire up so I think I'm either not getting fuel or not getting a spark.

What's a good starting point as far as things to test?


**I should note, the guy who rebuilt my engine installed a kill switch (pretty sure it's for the fuel injectors, in case the engine floods)