I have A Ford F-150 2002 it ran perfectly yesterday till mid day its motor is 5.4. When I put it into drive it goes forward and when putting it on reverse it doesn't run till all gas is put into it. When moving forward it goes half mile and the velocity goes down till there's nothing. What I want to know exactly is what is the problem? And as well as what can you recommend? For this issue at hand.
The truck is there and I'm not. All I know is it started acting up. I don't know if it shifts the way it's supposed to before it quits moving, if it sets any diagnostic trouble codes when it starts acting up, or if the automatic transmission fluid is at the proper level. I do know that I would check all three things (shift quality, DTCs, and ATF level) first.
If I'm barking up the wrong tree by looking at the transmission (in other words, the engine coughs and chokes and splutters before it dies) then I would check the DTCs and fuel pressure, look to see if the malfunction indicator light was lit or blinking, and try to remember whether I had just switched tanks or refueled the truck immediately before it started acting up.
This information would prevent me from what could be a lot of expensive -- and unnecessary -- parts swapping. (Not that parts swapping is in and of itself bad -- as long as it gets to the point quickly and directly. Like when I swapped out my old unreliable starter for a newly remanufactured unit to get away from that rotten flag terminal Ford used on their starters in 1994, when my truck was built.)