Aloha folks,

I'm resurrecting my Pops old 1989 F150, its the 5.0 EFI, I have at a problem that has me stumped, I got it running again, when it's in park or neutral it idles and runs fine, I put her in gear and she runs a little rough, when I quickly floor the accelerator, she dies, no sputtering no nothing, when I depress the accelerator slowly she runs fine till the rims come up fairly high then she'll just die, again no sputtering, this is in park and in gear, so far one gas tank is pristine, the other had rust and debris I took it out and am running on the one good tank which has a new fuel pump, new fuel filter, I changed out a faulty injector, not sure if the problem is even related to the fuel system, but she just has a history of parts that involved it gone bad... any ideas? Thanks in advance gang.

 

Get a gauge and check the fuel pressure. No point looking too far in any other direction until you know whether or not you have enough pressure.