Your cap be bad. As from your posts you stated that everything was new and it leaked... So you removed the injector and replaced the copper gasket and o-rings... Still leaks so... The cap is the only thing left. If you going to change locations use the number 2 cylinder. Its right up front of the drivers side head... No fuel filter in the way so its much easier to reach. About cleaning off the molding flash. Yes... I use an exacto knife around the very bottom of the cap. You can actually feel some ruff sharp flash sometimes...