Pour water into the bottom of the Instant Pot inner pot.
Add the pork loin fat side up.
Sprinkle the pork loin with salt and pepper.
Spread the orange marmalade on the top of the pork loin.
Sprinkle the thyme and garlic powder on top of the marmalade.
Pour the soy sauce into the water at the bottom of the pot.
Close and lock the lid.
Turn the pressure release valve to sealing.
Press manual high pressure and adjust the time to 8 minutes.
Once the cooking cycle has ended, let the pressure release naturally until the pork reaches 145F, about 30 minutes for a pork loin that is 2 inches thick or 40 minutes for a 2.5 inch thick pork loin.
Turn the pressure release valve to venting to release any remaining pressure.
Remove the pork to a cutting board, and tent with foil.
Let the pork rest for 10 minutes before slicing and serving.
Serve the pork drizzled with the cooking liquid, if desired.
Notes
Pork loin: Be sure to use pork loin, not pork tenderloin. Pork tenderloin would dry out in the cook time listed.
Kosher salt: If you don't have kosher salt, you can sub an equal amount of sea salt. Or you can use ½ teaspoon regular table salt.
Fresh thyme: If you prefer, you can use ¼-1/2 teaspoon dried thyme.
If you don't like thyme, rosemary makes a great substitute in this recipe. Just use an equal amount of chopped fresh rosemary or ¼-1/2 teaspoon dried rosemary.
Garlic powder: Be sure to use garlic powder, not garlic salt.
Soy sauce: I like to use lite or reduced-sodium soy sauce to better control the salt level.