Coleman stoves that burn liquid fuel such as white gas or Coleman fuel use fuel pumps to pressurize the fuel in the generator. When the fuel pump refuses to pressurize the fuel, the stove simply will not work. Troubleshoot the issue with a few tested tips from Coleman. Be sure to have a replacement O-ring, the black rubber piece that keeps the fuel pump airtight, on hand for the fix. When troubleshooting such items, always start with the easiest and most obvious fixes first.
Unscrew the fuel tank cap and check that there is adequate fuel in the tank. If the tank is empty or near empty the fuel pump will not work. Fill the tank with at least three-quarters of a tank of fuel. Screw the cap down tight.
Turn the fuel pump dial a half-turn counter-clockwise. Place a finger tip or thumb onto the small hole in the center of the dial and pull the dial up and out of the housing. Push and pull the dial with the hole covered. Failure to cover the hole when pumping will not pressurize the stove. Keep the hole covered when pumping. If the pump does not pressurize, proceed to the next step.
Dip the toothbrush into some degreaser and scrub the pump handle and the burners of the stove. Rid the burners and pump handle of any debris or grease that may compromise the air tight seals. Blow the debris away.
Unscrew the entire fuel pump mechanism. To do this, turn the fuel pump dial clockwise to lock it into position then reach just below it and turn the whole housing counter clockwise until it comes out of the stove.
Locate the O-ring on the fuel pump. The O-ring is near the base of the pump piston. Look for dry rot or cracks in the O-ring. If any damage is present, push the O-ring off the mechanism. Push the new O-ring onto the fuel pump and screw the entire unit back into the stove. Check that the tank is full and keep your finger tip or thumb over the hole on the pump dial. Pump the handle to pressurize.