I recently had the same trouble. Here is what I did:

1) Cleaned the throttle body. Required new gasket and at $1.50 this was the cheapest first step. This is an easy job and rewarding when you see how dirty it is. This did not fix the rough start but it is good maintenance.

2) Replaced thermostat in airbox. This was about a $13 part and also an easy job. The car started much easier but I am told, here, that this should not effect the car when the engine is cold. I agree, but something worked it starts strong.

While doing the above two, I also cleaned the hoses, checked and cleaned connections to the Air Mass sensor, gave everything a pull and visual inspection.

Now the car started great but ran rough at first.

3) I installed a new dist. cap and rotor and found a bad plug wire. I replaced the wires and the car runs great.

Good luck to you.