I have a 88 ranger 2.9 automatic extra cab. My brother in law gave me the truck because he thought the fuel pump was bad. When I got it the high pressure pump on the frame rail wouldn't come on. I turned the key on and off a few times and it started to work. It runs know but if I let it idle for about 5 mins or so it wants to stall out. When I drive it down the road it seems to do fine. When it shifts into overdrive and and is running around 2000 rpm it acts like its starving for fuel. If I give it more gas it will down shift and run fine again. Has any one experienced this and can help. Thanks David.

Have replaced the filter, and run a pressure test on the pump?

No I haven't replaced the filter yet. How do you check the fuel pressure From each pump?