rough idle, no acceleration, and charging system?

1997 FORD F-150
260,000 MILES • 5.4L • V8 • 2WD • AUTOMATIC
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CULLINGARBER
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  • 2 POSTS
i’m having issues with where it will spit and sputter when i try to crank it, eventually it will catch and rev really high. It also has barely any acceleration unless it’s in a sweet spot then it barely moves. It seems to do better when i put my battery on a charger, but I've had both battery and alternator tested. Both are good but it still eventually wears down. i’ve replaced fuel filters twice, oil, checked for vacuum leaks, bad wiring, cleaned EGR valve, I've checked all the fuses multiple times, cleaned mega amp fuses, cleaned battery terminals, cleaned ground. there are hammer marks on catalytic converter, EGR had some light brown hardened deposits in it, one spark plug wire has roughly an inch of insulation burned off from 2inch line, ground wire runs all the way down to back of starter, a black plastic piece is broken on throttle cable. i just bought this truck out of necessity and two months later realized the odometers had been removed and all except four warning lights never came on.
Aug 10, 2023 at 10:19 PM
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STRAILER
  • Experienced Mechanic
  • 55,249 POSTS
I would fix the spark plug wire first and then run the codes to see what comes up.

This guide can help:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Next, I would check the catalytic converter which this guide can help you with:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Also have you changed out the spark plugs? Please go over these guides and get back to us.
Aug 11, 2023 at 8:29 AM
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CULLINGARBER
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i haven’t attempted the spark plugs themselves, I've heard horror stories about them breaking off and can’t afford the kit to repair it right now, I've checked the wire order and as far as i can tell it’s right. i’ve heard a rattling sound from under the truck but not sure if it’s the exhaust pipe loose or cat and i can’t keep it running long enough to really check, i’ve been able here and there in emergencies to make it to the store down the road and right at first it’ll stutter i’ll end up killing and restarting, it’ll rev up high without pumping gas, drives decent enough till the end of the road (about a quarter mile) then on the highway drives like crap sometimes getting up past 40 sometimes not, three miles to store and on the way back it barely makes it but as soon as i turn back on my road it’s like it starts running great again? my wife noticed the same thing. i’ve got the bad spark plug wire isolated and hose around it with tape just to get it to go so i don’t think it’s shorting out in the turn or something. i have found the gray connector with the single wire on the alternator was broken so it doesn’t catch. no codes currently but it also doesn’t show any transmission page like it does with every other vehicle it just goes straight into engine idk if that makes any difference.
Aug 11, 2023 at 5:53 PM
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STRAILER
  • Experienced Mechanic
  • 55,249 POSTS
If you could upload a short video of what the truck is doing it would help. It sounds like the fuel pump is failing, but can I ask if you have replaced the fuel filter? Here is a generic guide to help you step by step with instructions in the diagrams below to show you how on your car:

https://www.2carpros.com/articles/how-to-change-a-fuel-filter

This video will show you how:

https://youtu.be/wi6kzRjk5to

Check out the images (below). Please let us know what happens.
Aug 14, 2023 at 3:28 AM
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