Choke / Fuel Pump Oil Pressure Switch Plumbing

Some GM vehicles use the oil pressure switch to control the electric fuel pump and the choke. (Vega was one) Later (pre fuel injection) vehicles used the same switch to light a warning lamp on the dash to indicate the choke was not coming off. The 3 bladed switch on the left hand side is the pressure switch. (standard aftermarket fuel pump saftey switch) The middle outlet is for a Mechanical Oil Pressure Guage, and the the factory pressure sender will be where the pressure gauge is now. Notice how the brass fittings are supported by the bracket bolted to the web of the block.


Wire the Choke into the electric fuel pump circuit. The choke will only be heated when the engine is running.