Honda Civic IV 1.5i 16V (90 Hp)1987, 1988, 1989, 1990, 1991: specs, Fuel consumption, Dimensions

The dual point injection system is a throttle body version of the programmed fuel injection. It uses two large injectors, mounted in the throttle body. The bottom injector injects fuel all the time below the throttle plate, and the top injector is used during start-up, and under high fuel demands. In the Honda manuals it is called the auxiliary injector, even though it fires all the time. The top injector that only fires at start-up, and under load conditions is called the main injector. The auxiliary injector fires once per each cylinder's intake stroke. The main injector is used to deliver fuel at start-up, and speeds above about 1100 RPM. This injector also fires once for every firing of a cylinder. The PW of the main injector varies widely since it is being driven by the load of the engine. The bodies of the two injectors are shaped differently and cannot be interchanged. Due to the way the injectors are mounted in the throttle body assembly, if the back o-ring leaks, unmetered fuel could get into the intake manifold. This system was only used on Civic DX models from 1988- 91.