Warm Up Regulator: Description and Operation

The control pressure regulator varies the pressure applied to the chamber above the control plunger in order to dampen plunger and air flow sensor plate movement and tailor fuel delivery to engine operating conditions. The regulator consists of a valve which is controlled by a bi-metallic arm and electric heating coil. The bi-metallic arm is heated both by the coil and by engine heat, and opens and closes the valve according to temperature.

When the engine is cold and no current is applied to the heating coil, the bi-metallic arm holds the valve open. When the engine is started in this condition the open regulator valve causes a low pressure condition in the upper plunger chamber, the plunger and sensor plate respond freely to varying air flow and air/fuel mixtures are enriched. As the engine runs, current is applied to the regulator heating coil and the heat of the engine warms the regulator. As the bi-metallic arm is heated the regulator valve closes, control pressure is increased in turn dampening sensor plate and control plunger action, and leaner air/fuel mixtures are provided.