Hesitation when accelerating from a stop???

My question is what would cause the hesitation from a stop when first starting out? Its like something is slipping and then catches & then it goes fine? Only happens when you first accelerate from a complete stop. When you get to 20+ or so mph it runs out fine. I just changed the timing belt & all other belts at the same time, about 2 weeks ago. Any info would be greatly appreciated. Thanks.
Craig

Bad cam timing. Vacuum leak. Slipping transmission.
Check your transmission fluid first. You drive a slipping automatic transmission at all and you'll burn it's clutches out & then you're stuck witha nasty repair bill.

Bad cam timing. Vacuum leak. Slipping transmission.
Check your transmission fluid first. You drive a slipping automatic transmission at all and you'll burn it's clutches out & then you're stuck witha nasty repair bill.

I think I have something like the slipping transmission. It's only when I first turn the car on though, it takes it a little while to click into gear after I shift.

But to answer the first guy, does it shimmy during hesitation? If so I'd put injector cleaner in first. Repairs are last resort.

Me again with the hesitation problem. I took the timing belt off & am going to tackle it again this evening. I downloaded the 93 fsm from here, awesome! I need to know which installation mark to align with the drilled mark of the crankshaft timimg pulley. There are a few green marks on the belt, some single lines & some double lines , plus a line of arrows. Which one goes with the drilled mark to start out with? Thanks for the help.

My 2003 ES330 will sometimes hesitate when you press the gas at city speeds 20-45 mph. Most of the time the car will "pause" a second before accelerating in response to the gas petal.
Any help?