Have you checked/changed out your MAF sensor.
I just had a terrible time diagnosong a very bad idle (especially when cold), that was worse when cold and seemed to get better after the engine warmed up but was still noticeably stumbling/missing.
Driveability was'nt really a problem however but sometimes I could tell it was missing. I actually removed the MAF sensor from the housing and cleaned the element with some carb cleaner and it cleared it right up.
I can't believe how much havoc that stupid sensor caused. I went through fuel injectors, coils, plugs, wires, DPFE sensor, checked egr valve function, replaced ground/starter/battery cables...........in short order a nightmare!
Just trying to help.
1995 Ranger Super
2.3 w/air intake
10" Type-R's w/RF Amp
Overbuilt's better then underbuilt. After a 12 pack of beer and a dare from your best friend.