Fuel Injector(s)

Samurai, Sidekick and Swift SOHC utilize Throttle Body Injection (TBI), which incorporates a single fuel injector in the throttle body unit. Swift DOHC utilizes Port Fuel Injection (PFI), which incorporates 4 fuel injectors mounted in a fuel rail assembly.

When the solenoid coil of injector is energized by ECM, coil becomes an electromagnet. This lifts injector plunger, allowing fuel under pressure to be injected into intake manifold (Samurai, Sidekick & Swift SOHC) or cylinder head (Swift DOHC). Since fuel pressure is relatively constant, air/fuel mixtures are controlled solely by injector pulse width ("on" time). ECM determines proper pulse width based upon input signals received from various sensors and switches.

Timing of injector firing is determined by ECM based upon RPM signals received from either distributor P/M generator (Swift) or ignition coil (Samurai, Sidekick and Swift SOHC). On Swift SOHC, ECM also monitors ignition coil signal. Since ECM interprets coil signals as an indication of spark presence, fuel injector triggering will cease if ignition coil signal is lost.

Fig 1: Typical Fuel PFI Injector (Swift Shown)

Courtesy of SUZUKI OF AMERICA CORP.

Fig 2: Typical Fuel TBI Injector (Sidekick Shown)

Courtesy of SUZUKI OF AMERICA CORP.