I have a Volvo 5.7 GSI TBI 280 Hp.When going from idle to WOT She bogs for about 30 sec. and the it's fine. If I go to WOT slowly She is fine. I have change Fuel pump, fuel filter, TBI unit and injectors, new cap, rotor, plugs, wires. Vacuum is 17 degrees. The top end RPM is 4800 mid range is good.
please HELP.