4EyedTurd1

iTrader: (1)

Backstory on this ‘99 5.3 was it was a running truck until the fuel pump quit. Buddy put a fuel pump in and it cranked and ran for less than a minute. He said it would barely idle at 300rpm. He pulled plugs and they are so worn the gaps are huge (over .1”). He tore a few wires so he quit messing with it. Fast forward a couple months. I put a fresh battery on it and the starter just clunks so I put a breaker bar on the crank bolt. It ain’t budging either direction. It’s got plenty of dirty oil in it and he ran it less than a minute so we’re both kinda stumped why it might’ve locked up. I even pulled the accessory belt off and tried a 4’ cheater on the breaker bar.

Ls7colorado

iTrader: (3)

It was probably barley runnning because a bearing/bearings was trying to seize up, now after sitting and cooling it wont turn.
Any metal/water in the oil?
How was it running before the fuel pump quit?

4EyedTurd1

iTrader: (1)

No water in the oil, and no metal that I can tell. I’ll try draining the oil thru a screen. Don’t know how it ran before the fuel pump died.

G Atsma

Tear-down time......

Che70velle

iTrader: (6)

Cut the filter open. It will tell you the story.

CattleAc

iTrader: (7)

It's probably not hydro locked since you tried to turn it both ways...but I would still pull the plugs and try to turn it over one more time...

4EyedTurd1

iTrader: (1)

Pulled the plugs and they were dry, still didn’t budge so I dumped out down each plug hole and tried. Im sure I’m just pissing in the wind at this point but I’d still like to find out the why.

Ls7colorado

iTrader: (3)

.......

Old Geezer

iTrader: (3)

"I’d still like to find out the why."

The why comes when you tear the damned thing down......

00pooterSS

iTrader: (40)

I'm gonna guess that it quit running and someone thought the fuel pump went bad. But instead it was the engine locking up. Don't get too caught up on that whoever guessed at the fuel pump was right.

I bet they were wrong and the engine was seizing. And that's why it's mysteriously seized now with now explanation or reason to seize. And that's why it would only idle at 300 after the fuel pump.

That's my guess anyway using my internet crystal ball.