1987 F150 with 5.0 fuel injectioned engine

My truck runs fine after it warms up for a couple minutes It's when I first start it - it stumbles and dies if I press on the accelerator to much or if I put it in gear and try to move forward or back.

It had a tuneup with, plugs, wires, cap, rotor and fuel filter. I even added some fuel injecton cleaner. But still the samething.

Any Ideas?

Thanks,
Bruce