General Motors

Vehicle has a pause or hesitation in acceleration between 35 & 39; the fault was acknowledged by Hall GMC and a separate transmission shop. However, both
diagnostic tests showed no mechanical faults on the vehicle.
The problem was investigated at the 97.5K mileage maintenance service when spark plugs, plug wires, transmission fluid, and transfer case items were replaced and again when torque convertor and a cracked manifold were replaced in an attempt to correct the problem.
Hall GMC said there are no computer updates available; however, please confirm there are no outstanding computer update and make a suggestion as to my next step in getting the problem corrected.
Glenda Penn