Jeep YJ Wrangler 4.2L Fuel Supply Issue or Vapor Lock in Jeep® YJ Wrangler, TJ Wrangler and LJ Wrangler Posted November 25, 2016 Fortunately the issue has been cured, had to replace the vent line, didn't find a steel one, so I had to put copper tubing instead of steel. Regarding the canister please see attached picture taken from under the vehicle. I still have an issue with the carb bowl getting empty after I let it sit over night. Any suggestion to fix this? (Return line from the filter is already on top, carb has been rebuilt - al gaskets replaced) thanks.