4JJ1 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 4JJ1 diesel engine family.
All Verified Part Numbers for 4JJ1
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.
| Part Number (SKU) | Primary OE Reference | Control Valve | Nozzle Code |
|---|---|---|---|
| 0445110748 → | 8974485560 | F00VC01359 | DLLA153P2521 (internal code 0433172521) |
Verified Vehicle Compatibility
| Make / Manufacturer | Vehicle Model & Platform | Engine Specification | Model Years |
|---|---|---|---|
| Isuzu | D-Max 3.0L TDCI | 4JJ1 3.0L TDCI | 2007-2016 |
| Isuzu | MU-X 3.0L TDCI | 4JJ1 3.0L TDCI | 2013-2019 |
| Isuzu | N-Series (NLR/NMR/NPR) 3.0L | 4JJ1-TC | 2007-2016 |
Installation, Tightening Torque & Re-torque Protocol
Strict torque compliance is mandatory on 4JJ1 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: 20 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 4JJ1, 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 4JJ1
What DTC fault codes indicate a failing injector on 4JJ1?
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 4JJ1 family be interchanged?
Not unless explicitly confirmed on the vehicle build plate. While sister SKUs share the same physical outer envelope and F00VC01359 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.