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Common Rail Cowboys

HP4 / 1KD Injector Pump Upgrade Kit

HP4 / 1KD Injector Pump Upgrade Kit

Regular price $2,300.00 AUD
Regular price Sale price $2,300.00 AUD
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Injector Pump Option
Quantity

HP4 / 1KD Injector Pump Upgrade Kit

✅ What’s Included
  • Adapter shaft & hardware kit
  • 3D-printed drilling jig for precise fitment
  • Genuine high-pressure pump-to-rail fuel line
  • Optional: Supply with or without HP4/1VD pump (new or BYO)

Note: Oil cooler modification required (cut & TIG weld aluminium). Fuel line must be bent to suit.

🧰 Installation Overview
  • Engine-in installation possible (easier during rebuild with timing case removed)
  • Jig included for accurate drilling & tapping of new pump mount holes
  • Oil cooler clearance mod required for larger pump body
    • DIY: Instructions provided for self-modification
  • Fuel temp sensor harness extension required (solder + heat-shrink recommended)
💡 Pump Options
  • Brand-new Genuine Denso HP4/1VD pump
  • Kit only — supply your own compatible pump

Note: For BYO pumps, the pump shaft is trimmed and the woodruff key removed. Full instructions included.

🔧 Tuning & Setup
  • Perform SCV (Suction Control Valve) relearn with a capable scan tool after install
  • Professional ECU calibration highly recommended to achieve target rail pressure and avoid over-fueling
  • Verify overall fuel system health (rail sensor, relief/blank, injectors, lines) prior to tuning
⚠️ Important Notes & Compliance
  • Use: Intended for off-road/competition applications where permitted. Check local regulations regarding fuel system modifications.
  • Warranty/insurance: Modifications may affect manufacturer warranty or insurance. Confirm with your provider.
  • Professional work advised: Pump machining, oil cooler modification and tuning should be performed by experienced technicians.
  • Post-install checks: Verify commanded vs actual rail pressure, check for leaks, clear DTCs and road test under load.
📦 Shipping & Payment
  • Fast Dispatch · Free Express Shipping Australia-Wide
  • Buy Now, Pay Later — Afterpay, Humm, Klarna & Zip

Frequently Asked Questions

Can I install the kit with the engine still in the vehicle?
Yes — engine-in installation is possible. It’s easier during a rebuild with the timing case removed, but the included drilling jig is designed to make in-car installs accurate.
Do I have to modify the oil cooler?
Yes — the larger HP4 body requires clearance on the oil cooler (cut & weld). DIY instructions are included, or have a fabricator handle it.
Will my stock ECU tune work after the swap?
You should plan for a custom ECU calibration. At minimum, complete an SCV relearn with a scan tool; tuning is recommended to command correct rail pressure and maintain drivability.
Can I use my own HP4/1VD pump?
Yes — choose the kit-only option. Your pump will require shaft trimming and woodruff key removal per the supplied instructions.
Do I need to modify wiring?
Yes — the fuel temperature sensor harness typically needs a short extension. We recommend solder and heat-shrink for reliability.
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