Blazer Probs

First off it is a 200 blazer LT with 90,000 on it now . When i first put the truck in drive and press the gas it hesitates for about 10 seconds then i have full power. I have tried new fuel filter and system cleaner but no improvements.............anyone have any input on this>>>>>????

this is killing me

have you checked your fuel pressure? The pressure should be around 60 PSI with the key on and engine off. Check that out maybe you need a new fuel pump itself. Cleaner doesn't always solve problems you know. I am thinking the hsitation might be coming from the pressure not being corretc right away and when you hit the gas the pump revs up and then increases the pressure to the proper level. I am not saying that is fully correct but that is my thinking so check that out and post back.