12668649
HITACHI 12668649 Iniettore Diretto GM Silverado Sierra Tahoe Yukon 5.3L 6.2L V8 EcoTec3 L83 L86 FJ1217
12623116, 12656932, 12668390, FJ1217, 842-12384, 12698484--150 barSpecifiche Tecniche
| Specifica | Valore |
|---|---|
| part_number | 12668649 |
| oem_reference | 12668649 |
| manufacturer | HITACHI |
| system_type | Fuel Injector |
| pressure_rating | 150 bar (2175 psi) |
| operating_temperature | -40°C to +135°C |
| flange_mount_torque | 12 N-m (106 lb-in) |
| high_pressure_line_torque | 28 N-m (21 lb-ft) |
| diagnostic_dtc | P0300, P0301, P0171, P0172 |
| Pressione di esercizioSpecifica Chiave |
Pompa alta pressione abbinata (Gruppo circuito carburante)
Funziona sullo stesso circuito ad alta pressione Common Rail. In caso di bassa pressione rail (P0087), verificare la portata della pompa prima di sostituire gli iniettori.
Istruzioni di montaggio
- Depressurize the fuel system completely via diagnostic scan tool or by removing the fuel pump fuse prior to line disassembly.
- Clean all surrounding bracket areas thoroughly using residue-free brake cleaner to prevent abrasive particulate ingress.
- Inspect the mechanical camshaft lobe and roller follower or clean injector bore seating surfaces before hardware alignment.
- Install component using fresh factory O-rings or Teflon combustion chamber seals lubricated only with clean motor oil.
- Torque mounting flange fasteners in alternating increments to 12 N-m (106 lb-in).
- Torque high-pressure hydraulic tube fittings using a calibrated flare nut wrench to 28 N-m (21 lb-ft).
- Prime low-pressure fuel circuit, cycle ignition key 3-4 times, and inspect for high-pressure hydraulic leaks before road test.
- Always replace single-use high-pressure metal fuel lines and micro-filter seals whenever disconnected.
- Verify camshaft driving lobe surfaces for scoring or flat spots before installing any mechanical pump.
- Reset long-term and short-term fuel trim adaptations via OBD-II diagnostic scanner after physical replacement.
Codici Guasto (DTC) e Protocolli Diagnostici
Codici guasto diagnostici (DTC) comuni generati quando questo iniettore common rail presenta usura, problemi ai circuiti o scostamenti:
Fuel Rail / System Pressure Too Low
Excessive internal backleak from worn control valve seats drops common rail pressure below target under engine load.
Injector Circuit Malfunction / Open Circuit
Solenoid coil resistance drift (0.2-0.5 Ω) or piezo stack degradation triggers driver stage shutdown on affected cylinders.
Cylinder Misfire & Balancing Deviation
Carbon-clogged nozzle spray holes or missing IMA calibration causes uneven cylinder contribution. Recode ECM and verify washer seating.
Fuel Rail / System Pressure Too High
Spill line backpressure or stuck metering valve prevents rail depressurization, creating overpressure risks under load.
Protocolli Tecnici di Diagnosi & Assistenza
Procedure d'officina verificate, valori soglia di test e linee guida operative per questo assieme.