2000 GMC Safari 2000 Safari hesitation

Engine Performance problem
2000 GMC Safari 6 cyl Two Wheel Drive Automatic 114k miles

Problem:
I have a 2000 safari with 115K miles. A few of months ago I noticed a jerk (hesitation) while driving. I would have the cruse on and the van would jerk sporadically, it did not constantly do it. Now it also does it when I accelerate. I feel it does it more when it is cold out, I have not determined if it happen more when there is less fuel in the tank. I have narrowed it down to engine; I can still feel/hear the hesitation when the van is in park.
The other problem I have is with acceleration. The engine revs up but the van does not move as fast as I feel it should be, then after 30 to 45 second it catches up. It feels like the trany is in two gears at the same time or the torch converter is not completely engaged. If I let up on the gas it catches up sooner. I hope this makes sense.

What I have done:
Recently I have replaced the coil, spark plugs and spark plug wires. Around 75k I had the injector cleaned and the trany flushed. I did replace the fuel filter 1 or 2 years ago.