I don't know if our two problems are related, but at random mine will be a pain to start as well. It doesn't seem to be connected to heat or the weather or anything, but then it hasn't happened yet this winter. When this happens the quickest way I've found to get it started is to hold the gas pedal to the floor and crank it (I've heard injected vehicles have a "flood clearing" setting at WOT and cranking?). When it does start it'll run terribly for a few seconds (by now I've let up a little on the pedal) and then off we go as if nothing happened.
Here's a shot in the dark: (input anyone?)
Could a mass airflow sensor stuck open a bit cause this kind of issue? I couldn't hurt to have a peek at it as it may be in need of a cleaning (unless this happened on your tune-up)
I really doubt this helps any but might get others thinking to at least shoot down my MAF theory.
Good luck!