I had my s750 bobcat repaired first it injector pump then injectors then turbo and the hole time it was a clogged muffler know it starts cold but not warm and I'm getting blow by bad
/ s750 replaced injectopump turbo and injectors ended up a cloged muffer butt it sounds
I worked on a Ford F-350 with 351 gas that had a stopped up muffler once.
Had the dumbest symptoms I have ever seen and kept me looking in the wrong direction.
Start it up, it would run for a minute then stall and built up pressure would hiss out of the carburetor!
It had me stumped and hating Fords didn't help.
Are you sure injector pump is timed right. Just a wild guess. ???