Berryman B-12 Chemtool Fuel System Cleaner (part #0116) is very effective at removing fuel injector deposits. However, the addition of specialized detergents can aid in the cleaning process, too. B-12 Chemtool Fuel Injector Cleaner (part # 1126) would typically be considered the most suitable for your application. While using a glass syringe would be preferable for your setup, HDPE and PP plastics should work, too. However, they must not have rubber components—some plastic syringes have softer, rubber gaskets on the plunger—and we recommend discarding the syringes after each use.