Disconnect injector connector at intake manifold.
Turn ignition on with engine off.
Using test light connected to ground, probe injector ignition feed circuits
test light should illuminates
Install injector test light to each injector circuit, one at a time. Crank engine. If injector test light flashes on each injector, check fuel injector(s).
Central Sequential Port Injection (CSI)
CSI is a non-repairable injector assembly consisting of a fuel meter body, fuel pressure regulator, fuel injector and poppet nozzles with fuel tubes. CSI assembly is housed in the lower manifold assembly. Fuel pump and pressure regulator maintain fuel pressure at 60-66 psi (4.2-4.6 kg/cm2 ) under all operating conditions.
When injector is energized, pressurized fuel passes down fuel distribution tubes to poppet nozzles located at rear of intake valves. Fuel pressure forces poppet valves open, spraying fuel into cylinders when intake valves are open. As fuel pressure drops (due to all poppets opening or injector de-energizing), poppet nozzle spring pressure closes poppet nozzle until pressure again builds high enough to overcome poppet nozzle spring pressure. Excess fuel is returned to the fuel tank via the fuel return line.
Sequential Fuel Injection (SFI)
Injectors on these models are pulsed sequentially in spark plug firing order. Main differences between sequential and simultaneous systems are injectors, wiring and the PCM/VCM.
Constant fuel pressure is maintained to the injectors. Air/fuel mixture is regulated by amount of time injector stays open (pulse width). Various sensors provide information to the PCM/VCM to control pulse width.
Thursday, December 2nd, 2010 AT 12:14 AM