Gjac wrote:
I would think your vehicle came with a fuel pump in the tank. Someone may have installed an external fuel pump also. There is a certain flow rate for each engine that needs to be met so engine can run at WOT. Pressure may be fine but if the flow rate is not there the engine will bog down.
As noted earlier, ours had a pump in the tank and another one on the frame rail. We replaced the one on the frame rail mid-trip after we were towed in. It was better, but not 100%. Once we replaced the in-tank pump it was back to 100%.
Others here have also noted an in-tank pump, the OP originally said he didn't have one, and I haven't seen anything where he has acknowledged the possibility there may actually be one.
The in-tank pumps of that vintage were known to be problematic too.