Nissan Navara: YD25DDTi High-Pressure Fuel Pump and Injector Failure

The YD25DDTi common-rail diesel system uses a high-pressure fuel pump (HPFP) and Bosch piezoelectric injectors that are sensitive to fuel contamination and wear. Pump failure typically results from cavitation caused by aerated or low-lubricity fuel. When the HPFP fails catastrophically it can shed metal particles throughout the entire high-pressure fuel circuit, contaminating injectors, fuel rail, and in severe cases the cylinder head fuel galleries. A full system failure requires replacement of pump, all injectors, fuel rail, and high-pressure lines — an expensive outcome. Early-stage pump wear presents as hard starting when hot and rough idle at low rpm.

• Difficulty starting when engine is hot, cranks but takes multiple attempts
• Rough idle and misfiring at low rpm
• Loss of power under load with intermittent surging
• Engine management warning light with fuel system fault codes

1. 1

   Scan for fault codes, particularly P0087 (fuel rail pressure too low) or P1272/P1273 injector balance codes.

2. 2

   Check fuel rail pressure with a calibrated gauge — low pressure at idle indicates pump wear.

3. 3

   Inspect fuel filter housing for metal debris or discolouration in the fuel.

4. 4

   Check for signs of previous injector or pump replacement.

5. 5

   Ask workshop to perform injector return-flow test to confirm injector health before purchase.

Parts involved: High-pressure fuel pump, Fuel injector.

$2,500 to $7,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the high-pressure fuel pump or any injectors been replaced?”
• “Has the vehicle been run on low-quality or contaminated diesel at any point?”
• “Are there any stored or historical fuel system fault codes?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.