Green’s Dictionary of Slang

poop-out n.

[poop out v. (2)]

a mechanical failure.

[US]G. & S. Lorimer Stag Line 136: Some poop-out of a system, that it.
[US]E. De Roo Go, Man, Go! 73: The Corvette had it on the macadam, but not on the oiled dirt. He felt puzzled about that. Why the poop-out?