A fluid pressure regulator has a high pressure side and a low pressure side separated by a plunger. The plunger is biased against fluid pressure on the low pressure side. The fluid pressure on the low pressure side in opposition to the biasing means moves a primary passage through the plunger into and out of flow communication with fluid on the high pressure side under normal conditions. A fine passage through the plunger moves into and out of flow communication with fluid on the high pressure side under start-up conditions.