Fuel Control
The fuel control system uses a small electric pump to provide fuel at varying pressure to the injectors. Unlike other EFI systems (GM and Ford), the injectors spray constantly. The Chrysler system controls the amount of fuel flowing, rather than the time the injectors are open. The entire fuel control system is mounted on the fuel support plate, above the throttle body.
A flowmeter and temperature sender enable the computer to calculate the amount and density of fuel going to the injectors. The pressure switch is normally open when the engine is running. However, during cranking, pressure is low, so the switch closes and drives the control pump at full speed until the pressure is up to normal. This ensures quick starting.
The injection assembly contains 2 valves. The Light Load valve opens above 21 psi and allows fuel to flow through 4 holes in the light load bars. Fuel is sprayed into the throttle body and atomized further by ridges on the throttle blades. When fuel pressure exceeds 34 psi, the Power valve opens and allows fuel to spray through the power bars. This normally occurs only during starting and full-throttle operation.