Heinekens has the same gas content as most domestics. If your liquid temperature is 38, 14 PSIG with about 4-5' 3/16" ID line. Coors products should be 16 PSIG. Labatts also at 14 PSIG. For every two degrees warmer, up one pound; colder - down one pound. Be sure that no pressure leaks are present and faucets and keg couplers/valves are clean.
Scott Zuhse, Instructor
Micro Matic Dispense Institute