buick stalling

I have an 89 with the 4 cylinder engine. When its cold, on a cold start, my car will start really slow and rough. It will run but it sputters a little bit. Like its missing. There is a lack of power. If you go ahead and drive it runs like that for about 20 seconds and then the power returns and it drives just fine. Any thoughts?

2.5? Any codes? Last tuneup(with wires)? Check coil output?

Yes 2.5 i don't know if you need the tool to scan codes or not on this car since its rather old. do you know how?

Jump a and b terminals on the diagnostic link under the dash, then count the flashes.