Control Pressure Regulator
The control pressure regulator provides fuel pressure to the top of the plunger in the fuel distributor. Reduced pressure allows the plate to move farther with the same air flow. This supplies more fuel to the cylinders to improve warming up. As the engine reaches operating temperature (or a pre-determined time elapses) the control pressure regulator increases control pressure, leaning the air/fuel mixture.
A bi-metal strip in the control pressure regulator is heated by an electric coil. As it heats up, it gradually increases the control pressure. If the electrical connections are not good, the warm-up function of the regulator will not operate. Some regulators have an altitude-sensitive function that compensates for changes in barometric pressure.