sounds like the throttle position sensor needs adjusted. or it could be the fuel filter too. dirt could be settling in it overnight and slowing down the flow of fuel.
Hey man, check the throttle body/intake. I had this same problem on a 92 toyota, and on my 02 grand cherokee, it just gets dirty and sticks until everything warms up. $5.00 for a can of intake cleaner later, and it fixed the problem both times.
