DELPHI EFI Fuel Injectors 2. Disconnect electrical connector from an injector and listen for a change in idle performance (only running on one cylinder) or a change in injector noise or vibration. If an injector is not operating, it can indicate either a bad injector, or a wiring/electrical connection problem. Check as follows: 1. Disconnect electrical connector from both injectors. Plug a 12 volt noid light into one connector. 2. Make sure all safety switch requirements are met. &UDQNHQJLQHDQGFKHFNIRUADVKLQJRIWHVWOLJKW Turn key OFF for at least 10 seconds between tests to allow ECU to go to sleep and reawake. Repeat test at other connector.
D ,IADVKLQJRFFXUVXVHDQRKPPHWHU5[VFDOH and check resistance of each injector across two WHUPLQDOV3URSHUUHVLVWDQFHLVџ,ILQMHFWRU resistance is correct, check whether connector and injector terminals are making a good connection. If resistance is not correct, replace injector. Check all electrical connections, connectors, and wiring harness leads if resistance is incorrect. Injector leakage is very unlikely, but in those rare instances it can be internal (past tip of valve needle), or external (weeping around injector Orings). Loss of system pressure from leakage can cause hot restart problems and longer cranking times.
To check for leakage it will be necessary to loosen or remove blower housing which may involve removing engine from unit. Refer to Disassembly for removal of injector. 1. Remove manifold mounting bolts and separate throttle body/manifold from engine leaving TPS, high pressure fuel line, injectors and fuel line connections intact. Discard old gaskets. 2. Position manifold assembly over an appropriate container to capture fuel and turn key switch ON to activate fuel pump and pressurize system. Do not turn switch to START position. Details NOTE: Do not apply voltage to fuel injector(s). Excessive voltage will burn out injector(s). Do not ground injector(s) with ignition ON.
Injector(s) will open/turn on if relay is energized. NOTE: When cranking engine with injectors disconnected, fault codes will be registered in ECU and will need to be cleared using software fault clear or an ECU Reset and TPS Learn Procedure. Injector problems typically fall into three general categories: electrical, dirty/clogged, or leakage. An electrical problem usually causes one or both of injectors to stop functioning. Several methods may be used to check if injectors are operating. 1. With engine running at idle, listen for a buzzing or clicking sound. NOTE: Fuel pump module pins are coated with a thin layer of electrical grease to prevent fretting and corrosion.
Do not attempt to remove electrical grease from fuel pump module pins. 3. If either injector exhibits leakage of more than two to four drops per minute from tip, or shows any sign of leakage around outer shell, turn ignition switch OFF and replace injector as follows. 4. Depressurize fuel system. 5. Clean any dirt accumulation from sealing/mounting area of faulty injector(s) and disconnect electrical connector(s). 6. Pull retaining clip off top of injector(s). Remove screw holding injector(s) from manifold. 35 24 690 01 Rev. D KohlerEngines.com WARNING ([SORVLYH)XHOFDQFDXVH¿UHVDQGVHYHUH burns. Fuel system ALWAYS remains under HIGH PRESSURE.
Wrap a shop towel completely around fuel pump module connector. Press release button(s) and slowly pull connector away from fuel pump module allowing the shop towel to absorb any residual fuel in high pressure fuel line. Any spilled fuel must be completely wiped up immediately. B A C D E F G H I A Electrical Connection B Upper Oring C Solenoid Winding D Armature E Valve Housing F Valve Seat G Valve End H Lower Oring I Director Plate