Strange problem

I recently purchased a 1995 Chevy Tahoe it has the stock tbi 350 and runs really good except for one strange thing. It idols beautifully and from 2000rpm and above it absolutely hauls ass but from 1000rpm to 2000rpm it acts like it's starving for fuel it reminds me of something running outof gas but if you stomp on it a little and get it to 2000rpm it runs great and when you let off it idols great. Also it has all new plug wires, spark plugs, distributor cap, air filter and fuel filter and none of these fixed the problem. So its got me confused PLEASE HELP!