Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9 Diesel Injector
Cross-Reference & Technical Specs
Authoritative technical specifications, verified Bosch part numbers, control valve stamping codes, nozzle spray orifices, and hold-down tightening torque for the Honda 1.8L i-VTEC SOHC R18A1 diesel engine family.
All Verified Part Numbers for Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9
The following 1 common-rail injector assembly is calibrated for this engine family. Click the SKU to view individual test bench flow curves, sister cross-references, and vehicle applications.
Bosch 16450-RNA-A01 Common Rail Injector for Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9 →
KEIHIN CRISee Product DetailNozzle Code: See Product Detail| Part Number (SKU) | Primary OE Reference | Control Valve | Nozzle Code |
|---|---|---|---|
| 16450-RNA-J01, FJ786, 842-12328 | See Product Detail | See Product Detail |
Installation, Tightening Torque & Re-torque Protocol
Strict torque compliance is mandatory on Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9 common-rail cylinder heads. Over-torquing stretches the injector body or strips the head clamping threads, while under-torquing allows combustion blow-by past the copper sealing washer:
- Hold-down clamp bolt: 12 N·m (cold state). Always clean the cylinder head recess with an injector seat reamer.
- High-pressure rail flare nut: 25-30 N·m using a dedicated 17 mm line wrench.
- Return leak-off banjo bolt: 9-12 N·m with fresh copper washers on both sides of the banjo union.
After fitting replacement injectors on Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9, generate or program the cylinder-specific IMA calibration code into the engine ECU using an OEM-level scan tool (Bosch KTS, Renault CLIP, or VAG-COM) to prevent cylinder power imbalance and rough idle.
Technical Diagnostics FAQ for Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9
What DTC fault codes indicate a failing injector on Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9?
The most frequent fault codes are P0201 through P0204 (Injector Circuit Malfunction on Cylinders 1-4), P2146/P2149 (Injector Group Supply Voltage Error), and P0087 (Fuel Rail Pressure Low due to excessive internal leak-off). Measure solenoid coil resistance across the pins (0.5-1.5 Ω) and perform a graduated-bottle dynamic leak-back test to pinpoint the leaking cylinder.
Can sister SKUs within the Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9 family be interchanged?
Not unless explicitly confirmed on the vehicle build plate. While sister SKUs share the same physical outer envelope and See Product Detail control valve, they differ in nozzle spray orifice angle and factory IMA flow calibration. Mixing sister SKUs on the same engine block can trigger rough idle, elevated exhaust gas temperatures (EGT), and MOT emissions failure.
Which specific Bosch injectors fit the Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9 engine?
The verified genuine Bosch common-rail injectors engineered for the Honda 1.8L i-VTEC SOHC R18A1 / R18Z1 / R18Z9 engine family are:
- Bosch 16450-RNA-A01 Common Rail Injector → (OE: 16450-RNA-J01, FJ786, 842-12328) —