16630-5CA0A
HITACHI 16630-5CA0A High Pressure Fuel Pump Nissan VR30DDTT 3.0T
16630-5CA0A, 16630-5CA0B, 16630-5CA1A, 16630-5CA2AIntegrated Electronic Pressure Regulating Spill Valve-200 barProduct Overview
The Hitachi 16630-5CA0A (Nissan OE 16630-5CA0B / 16630-5CA2A) is the original equipment high-pressure mechanical fuel pump for Nissan and Infiniti VR30DDTT 3.0L Twin-Turbo V6 engines. Driven directly by an auxiliary exhaust camshaft tri-lobe via a roller tappet (Nissan OE 13038-5CA0A), this precision radial plunger pump compresses low-pressure feed fuel up to continuous direct-injection rail pressures of 200 bar (2900 psi). Fitted to high-performance applications including the Infiniti Q50 3.0t, Q60 Red Sport 400, and the Nissan Z (RZ34), it features an integrated pulse-width modulated spill valve. Pump failure causes extended cranking times, severe power stutter above 4500 RPM, and diagnostic trouble codes P0087 and P0172.
OIL DILUTION & HIGH-RPM RAIL COLLAPSE WARNING: On tuned or high-mileage VR30DDTT engines, worn HPFP plunger shaft seals leak raw gasoline into the timing chain cover, diluting engine oil, inflating dipstick oil levels, and triggering P0172 rich codes. Furthermore, a degrading internal check valve cannot sustain 200 bar at wide-open throttle (WOT), causing rail pressure to plummet below 50 bar and triggering abrupt engine limp mode with DTC P0087 (Fuel Rail Pressure Too Low).
Vehicle & Engine Fitment
Technical Specifications
| Specification | Value |
|---|---|
| Pump Generation | Hitachi Radial Plunger High Pressure Fuel Pump |
| Operating Rail PressureCore Spec | |
| Cam Drive Type | Exhaust Camshaft Tri-Lobe via Roller Tappet |
| Roller Tappet Part Number | Nissan OE 13038-5CA0A (Inspect for flat spots) |
| Solenoid Metering Valve | Pulse-Width Modulated Normally-Open Spill Valve |
| Pump Flange Mounting Torque | 10 N·m (M6 Bolts, alternating two-step torque) |
| High Pressure Pipe Flare Nut Torque | 30 N·m (19mm flare nut, counter-held body) |
| Tightening Torque | 30 N·m |
| Hold Down Torque | 10 N·m |
| Default Safety Pressure Mode | Mechanical bypass ~5.0 bar low pressure feed |
| Operating PressureCore Spec |
Matched High-Pressure Fuel Pump (Fuel Circuit Assembly)
Operates on the same high-pressure rail circuit. When troubleshooting low rail pressure (DTC P0087), verify pump volumetric delivery before replacing injectors.
Installation Tips
Tools needed: 19mm line flare wrench and open-end backup wrench, Torque wrench calibrated for 10-30 N·m range, 10mm socket, ratchet, and extension bar, Clean engine oil or assembly lubricant for roller tappet and O-ring, Shop towels and eye protection for high-pressure fuel release
- Disconnect the vehicle negative battery terminal; remove the fuel pump fuse and crank engine for 5 seconds to depressurize the fuel lines.
- Wrap clean shop towels around the high-pressure fuel line fitting and slowly loosen the 19mm flare nut to vent residual rail pressure.
- Disconnect the wiring harness from the fuel pressure regulator spill valve solenoid.
- Disconnect the quick-connect low-pressure fuel supply line from the pump inlet fitting.
- Loosen the two 10mm pump flange mounting bolts evenly in half-turn increments to relieve spring tension from the camshaft lobe.
- Remove the pump from the cylinder head cover; extract roller tappet 13038-5CA0A and inspect for free rotation and surface pitting; replace if scored.
- Clean the cylinder head mounting surface and lubricate the new pump O-ring seal with clean motor oil.
- Rotate the crankshaft until the camshaft driving lobe is on its base circle (lowest lift point).
- Insert the lubricated roller tappet into the bore, seat the pump, and start the mounting bolts finger-tight.
- Torque the two mounting bolts alternately in two progressive steps to 10 N·m.
- Thread the high-pressure steel pipe flare nut by hand to prevent cross-threading; counter-hold the pump body adapter and torque flare nut to 30 N·m.
- Reconnect low-pressure fuel supply line and wiring connector; cycle ignition three times to prime system and inspect for leaks.
- Counter-Holding Hex Fitting Mandate: Always counter-hold the pump body hex adapter with an open-end wrench when torquing the 19mm high-pressure flare nut to 30 N·m. Torquing without counter-holding twists and loosens the factory-calibrated pump fitting.
- Camshaft Base Circle Alignment: Rotate the engine so the cam lobe is at lowest lift before tightening mounting bolts. Bolting down the pump against peak lobe lift cross-threads aluminum threads in the cylinder head.
- Mandatory Oil Change After Diaphragm Breach: If replacing the pump due to strong gasoline odor or rising oil dipstick levels, perform a complete engine oil and filter change immediately to protect turbocharger journal bearings.
Frequently Asked Questions
What diagnostic codes indicate a failing 16630-5CA0A HPFP on Infiniti Q50 3.0t?
The primary DTC is P0087 (Fuel Rail Pressure Too Low), which triggers engine limp mode and cuts boost during hard acceleration. If the internal plunger shaft seal fails, fuel dilutes the crankcase oil, triggering false rich codes P0172 and P0175 through PCV vapors.
Why does my Infiniti Q60 or Nissan Z smell strongly of gasoline on the oil dipstick?
On the VR30DDTT engine, the high-pressure mechanical pump is mounted directly over the timing drive valvetrain. When internal plunger seals degrade, fuel bleeds directly into the engine oil cavity. An overfilled dipstick smelling like raw gas is a definitive indicator of HPFP failure.
Do I need to replace the roller tappet when installing a new VR30 HPFP?
Yes. Standard ASE practice requires inspecting roller tappet 13038-5CA0A whenever the pump is removed. If the internal needle bearings develop flat spots, the tappet scores the exhaust camshaft drive lobe, requiring costly camshaft replacement.
Say this to the shop: How can the technician confirm HPFP failure before replacing it?
Ask the technician: 'Please hook up CONSULT-III or a data logger and record Fuel Rail Pressure Target vs Actual during a full-throttle 3rd gear pull. If low-pressure feed holds steady at 5.0 bar while high-pressure actual drops 50+ bar below target, the HPFP is confirmed faulty.'
Diagnostic Trouble Codes & Fault Protocols
Common diagnostic trouble codes (DTCs) triggered when this common rail injector experiences wear, circuit faults, or calibration drift:
Fuel Rail / System Pressure Too Low
Excessive internal backleak from worn control valve seats drops common rail pressure below target under engine load.
Injector Circuit Malfunction / Open Circuit
Solenoid coil resistance drift (0.2-0.5 Ω) or piezo stack degradation triggers driver stage shutdown on affected cylinders.
Cylinder Misfire & Balancing Deviation
Carbon-clogged nozzle spray holes or missing IMA calibration causes uneven cylinder contribution. Recode ECM and verify washer seating.
Fuel Rail / System Pressure Too High
Spill line backpressure or stuck metering valve prevents rail depressurization, creating overpressure risks under load.
Cross-Reference & Compatibility
Sister parts, same-platform variants, and known incompatibilities.
Technical Diagnostic & Service Protocols
Authoritative field procedures, diagnostic testing thresholds, and service SOPs for this assembly.