Combine potatoes, peppers, sausage, onions, oil, paprika, thyme, salt and pepper in a large bowl.
Cut 8 pieces of heavy-duty foil, about 12 by 17 inches each. Coat one piece with cooking spray. Place about 2 cups of the potato mixture in the center of the coated foil and enclose like a package. Place seam-side down on a second piece of foil and enclose again so the potato mixture is wrapped in a double-thick packet. Repeat with the remaining foil and potato mixture, making 4 total packets.
Prepare a campfire and let it burn down to the coals. Cook the packets 4 to 6 inches above the coals, turning once or twice, until vegetables are tender, about 25 minutes.
