I have a 1985 F150 XL with the 302 fuel injected engine I had a brake booster put in 3 months ago while I was driving home it died so they towed it back and said fuel pump went bad they replaced both fuel pumps . Picked it up ran good let it sit in driveway for a couple days went to start it wouldn't start brought it to a different mechanic he suggested full tune up plugs rotor and wires picked it up ran great for a day or two then stopped again . Brought it to another mechanic he said the heat sensor was bad or something they replaced it went to pick it up only way to keep it running was give it gas until engine was warm so drove it home and all's it did was spudder and back fire the whole ride. Sent it back to that mechanic he said the wiring harness is **** so he replaced a bunch of wires now it will start and when it idles it boggs down almost stals and kicks back up to normal idle it does this for a couple minutes then idles fine but when u drive it it still spudder and has no power and back fires the whole time. Any help or suggestions would be greatly appreciated