Hi everyone I am having a problem with my 89 f150 with a 5.0l in it. This problem just stared this winter. When I go to rev truck up just sitting from about 1000 to 2000 rpm it will cutout bad and eventually backfire through intake sometimes it will just almost die. But if I rev it up more it pulls out of it and revs fine until i let it idle again and then rev it. I have replaced fuel filter and cleaned egr valve out still no sign of getting better. When I go to drive the truck I have to slip the clutch bad just to get it to drive and everytime I shift from 1000 to 2000 rpm the truck will barely drive but after I get it past that rpm it will drive fine until I upshift again then it falls on its face. It seems when I have even more of a load it won't move at all it just tries to die like if i put it in 4 wheel drive i cant get the truck to move but it never dies just has no power what so ever and won't pull itself.