My son is restoring a neglected 1986 F150, 6 cyl engine, manual trans, 2WD.
He took it to work yesterday and it came home on the end of a tow strap.
He said it was okay running short trips around town during the day but if he tried accelerating too quickly or when he was in overdrive, it would lunge, misfire, run poorly. Finally got so bad it couldn't be driven any further and quit with the loudest backfire he's ever heard. Blew a hole in the rusty muffler. He was running on fresh gasoline.
Question: any mechanic types here got any good suggestions as to what went wrong and where we should start looking?
This is going to be a good truck once he gets it running well.
-Len

 

Not much anyone can do but guess, given so little information about the truck, its history, and what your son has done to it. Tell him to click this, read the caption, and put ALL its details into his signature:

(phone app link)

 

Turns out the filter at the carb was clogged, starving the engine of fuel and running it lean.