Toyota Prado: 1KZ-TE Injection Pump Timing Drift and Shaft Seal Leak (Bosch VE)

The Bosch VE rotary injection pump fitted to the 1KZ-TE is prone to internal wear that causes injection timing to drift retarded over time. As timing slips, combustion efficiency drops, producing excessive black or grey smoke, poor cold-starting, rough idle, and a loss of mid-range torque. The pump throttle shaft seal also deteriorates with age, allowing diesel to weep externally. Toyota service documentation specifies injection timing verification at major services, but many imported vehicles arrive in Australia without this ever having been performed. A specialist diesel workshop is needed for correct adjustment.

• Excessive black or dark grey smoke under acceleration
• Hard starting, particularly in cold weather
• Rough or lumpy idle
• Noticeable loss of power in the mid RPM range
• Diesel smell or staining at the injection pump body from shaft seal leak

Cold-start the engine and blip the throttle — black smoke suggests retarded timing. Check the base and sides of the injection pump body for diesel wetness or staining indicating a shaft seal leak. Ask whether injection timing has been verified by a diesel specialist in the last 50,000 km. A diesel specialist with a laptop or timing light can measure pump timing in under 30 minutes.

Parts involved: High-pressure fuel pump.

≈A$550 to ≈A$2,300 at independent workshop rates, shown as an approximate guide in Australian dollars. That is for this job on its own, not for the car.

An estimate, converted to Australian dollars, 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 injection pump timing been verified or adjusted in the last 50,000 km?”
• “Has the pump shaft seal been replaced?”
• “Does the engine start cleanly in cold weather?”
• “Is there any black smoke under hard acceleration?”

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.