Key Features And Applications

This Delphi high-pressure injection pump is designed for 2.0 HDi RHR engines with approximately 100 kW output. It is compatible with multiple Stellantis applications and related platforms, commonly fitted to vehicles such as Citroën C5 (including X7) and Peugeot 407, and found in certain Ford, Volvo and Mazda diesel models that share the 2.0 HDi RHR configuration. The pump uses the DELPHI 5WS40019 control system and is supplied without an integrated fuel pressure regulator.

Why Choose This Pump

Ideal for professional workshops and experienced DIY mechanics looking for an exact-fit replacement by part number. The pump matches original equipment specifications for delivery and control when installed and timed correctly. Frequent search terms include part numbers 9656391680, 9424A000A, 1920LP and 1921N3 — entering these codes will help you find the right unit quickly.

Technical Information

• Manufacturer: Delphi
• Model: Injection Pump 2.0 HDi RHR 100 kW
• Product Codes: 5WS40019
• Other Numbers: 9656391680, 9424A000A, 1920LP, 1921N3

Installation Recommendations

• Preparation: Work On A Cold Engine, Disconnect The Battery And Relieve Fuel System Pressure Before Starting.
• Timing: Mark And Align Engine Timing And Pump Timing Marks Precisely. The Pump Must Be Installed With Correct Angular/Timing Position To Avoid Engine Damage.
• Seals And Fittings: Replace All Gaskets, O-Rings And Banjo Fittings; Use New Seals To Ensure Leak-Free Operation.
• Bleeding: Prime And Bleed The Fuel System Thoroughly After Installation To Remove Air; Use A Hand Primer Or Diagnostic Tool Where Available.
• Electrical And Calibration: Verify Electrical Connections And Actuators. Some ECUs May Require Adaptation Or Clearing Of Fault Codes After Replacement.
• Final Checks: Inspect For Leaks, Check Fuel Pressure And Perform A Road Test To Confirm Smooth Idle And Delivery Across The Rev Range.
• Recommendation: If You Are Unsure About Timing Or Calibration Steps, Use Professional Workshop Tools Or Seek Assistance From A Trained Technician.

Most Common Causes Of Failure

High-Mileage Wear: Pump components such as plungers and delivery valves wear over time, especially beyond 150,000 km depending on service history. Contaminated Fuel: Dirt, water or poor-quality diesel accelerates internal wear and can seize moving parts. Fuel Supply Issues: Faulty lift pumps, clogged filters or air ingress cause cavitation and premature damage. Electrical Or Control Faults: Failures of solenoids or control actuators in the DELPHI system can disrupt timing and delivery. External Leaks: Degraded seals and connections lead to loss of pressure and performance.

Practical Notes For Mechanics And DIYers

Search By Part Number For Fast Identification: Use OE Codes 9656391680, 9424A000A, 1920LP or the DELPHI reference 5WS40019 to locate the matching pump. Check Fuel And Filter Condition Before Installing A New Pump To Avoid Early Re-Failure. Keep A Record Of Mileage And Symptoms — Typical Signs Of A Failing Pump Include Hard Starting, Loss Of Power, Excessive Smoke And Fuel Leaks.

High-quality Siemens VDO injection pump designed for 2.0 HDi (100 kW) RHR/RHK engines. Intended for professional workshops and experienced DIY mechanics, this unit restores reliable high-pressure fuel delivery for stable combustion, improved starting and smoother engine response. The integrated fuel pressure regulator helps maintain consistent rail pressure under varying loads, which is essential for common-rail diesel systems. This pump is often searched for by part numbers such as 5WS40019, 5WS40809, 1920QH and 1920N8 — making fast identification and ordering simple.

Technical Information

• Manufacturer: Siemens VDO
• Model: 2.0 HDi 100 kW RHR / RHK Injection Pump
• Product Codes: 5WS40019, 5WS40809
• Additional Numbers: 1920QH, 1920N8, 131000

Compatible Models

Fits a range of Citroën and Peugeot vehicles with the 2.0 HDi RHR/RHK engines, including Citroën C4, Citroën C4 Picasso, Citroën C5, Citroën C5 X7, Citroën C8, Peugeot 307, Peugeot 407 and Peugeot 807. Also used in certain Ford, Volvo and Mazda applications that share the same 2.0 HDi engine architecture.

Replacement Procedure

• Disconnect the negative battery terminal before beginning any work.
• Depressurize the fuel system and capture any fuel spillage safely.
• Remove engine covers, air intake components and any obstructions to access the pump.
• Mark timing/reference positions if the pump is connected to the timing drive and remove the drive belt or timing connection as required.
• Carefully disconnect fuel lines and electrical connectors; cap lines to prevent contamination.
• Unbolt the pump and remove it. Install the replacement pump in reverse order, ensuring correct timing alignment and secure fasteners to manufacturer specifications.
• Prime and bleed the fuel system, reconnect the battery, then start the engine and check for leaks, stable idle and correct fuel pressure.

Always follow the vehicle manufacturer’s service procedures for timing, torque values and bleeding. Incorrect timing or improper installation can cause serious engine damage.

Installation Recommendations

• Recommended For Professional Fitment: Suitable for qualified technicians or experienced mechanics with access to proper tools.
• Work Clean: Keep fuel lines and connections free of dirt to avoid contamination of the high-pressure system.
• System Checks: After installation, verify fault codes, confirm correct fuel pressure and ensure injection timing is correct.
• Safety: Always disconnect the battery before removal/installation to protect electronic components and prevent accidental cranking.

Why The Part Most Commonly Fails

High-pressure injection pumps most commonly fail due to contaminated fuel (dirty diesel or clogged filters), wear of internal components at high mileage, degraded seals, air ingress or overheating. Failures of the fuel pressure regulator or inadequate lubrication further accelerate wear. Regular fuel filter replacement and using clean fuel considerably extend pump life. Depending on maintenance and operating conditions, issues commonly appear after roughly 150,000–300,000 km.

Designed for quick identification by part number and built to match original specifications, this Siemens VDO injection pump is a practical solution for restoring performance and fuel system reliability on 2.0 HDi engines.

This high-pressure fuel injection pump is designed for 2.0 HDi diesel engines (100 kW), equipped with Siemens VDO components and an integrated fuel pressure regulator. It delivers precise fuel metering and pressure to the injection rail, ensuring stable combustion and smooth engine performance. Ideal for professional workshops and skilled DIY mechanics who service Citroën and Peugeot diesel engines.

Compatibility / Typical Applications

• Engine Codes: RHR, RHK (2.0 HDi, 100 kW)
• Common Vehicle Applications: Citroën C4, Citroën C4 Picasso, Citroën C5, Citroën C5 X7, Citroën C8; Peugeot 307, Peugeot 407, Peugeot 607, Peugeot 807
• Also Listed For: Selected Ford, Volvo and Mazda models using the same 2.0 HDi powertrain (see engine code RHR/RHK)

Technical Information

• Manufacturer: Siemens VDO
• Model: 2.0 HDi 100 kW (RHR / RHK)
• Product Codes: 5WS40019, 5WS40809
• Other Numbers: 1920QH, 1920N8, 9658193980, 9688153080, 131000

Function And What To Expect

The pump pressurizes diesel fuel and supplies it to the common-rail/high-pressure fuel rail (depending on application) according to signals from the engine management system. The integrated pressure regulator controls rail pressure to match engine load and injection demands. Proper operation is critical for fuel economy, emissions and driveability.

Typical Failure Causes

• Contaminated Fuel: Particles, water or degraded fuel cause accelerated wear of internal components and valves.
• Wear And Age: High mileage leads to internal wear, reduced pressure capability and erratic metering.
• Failed Pressure Regulator Or Seals: Loss of pressure control or external/internal leaks.
• Poor Maintenance: Clogged filters or irregular service intervals increase failure risk.

Replacement / Installation Notes

Replacing a high-pressure injection pump requires mechanical skill and attention to safety. Typical steps used by experienced technicians:

• Relieve fuel system pressure and remove fuel pump relays/fuses following the vehicle service manual.
• Disconnect the battery before beginning work.
• Clean the area around the pump and fuel lines to avoid contamination when lines are opened.
• Label or mark high-pressure lines to preserve their original positions if reusing them; then carefully disconnect fuel lines and electrical connectors.
• Remove mounting bolts and extract the pump. Replace all seals and gaskets with new parts.
• Install new pump, torque fasteners to the manufacturer’s specification and reconnect lines and electrical harnesses.
• Prime the fuel system and bleed air from fuel lines following the service procedure. Check for leaks at operating pressure.
• Perform a test start and check for correct operation, idle stability and absence of leaks.

If the vehicle requires pump timing adjustment or adaptation procedures, these should be carried out with the appropriate diagnostic equipment or by a qualified workshop.

Recommended Workshop Advice

• Always use clean, high-quality diesel and replace fuel filters at recommended intervals to prolong pump life.
• Install new sealing rings and gaskets during replacement to prevent leaks.
• After installation inspect for leaks and proper rail pressure before road testing.

Why Choose This Unit

Original Siemens VDO components and reference codes included in this listing make this injection pump a direct-fit solution for many 2.0 HDi applications. The integrated regulator ensures correct pressure control, restoring engine performance, drivability and fuel efficiency when the original pump is worn or faulty.

Installation of this regulator is straightforward for both professional mechanics and DIY enthusiasts. Typically, the replacement process involves disconnecting the fuel lines and mounting the new regulator securely in place. Regular maintenance and timely replacement are essential, as fuel pressure regulators can wear out over time due to exposure to heat and contaminants in the fuel system.

Functions of the fuel pressure regulator include maintaining the correct fuel pressure supplied to the engine for optimal combustion. A malfunctioning regulator can lead to poor engine performance, resulting in rough idling and increased fuel consumption.

Technical Information

• Manufacturer: Siemens VDO
• Model: X39-800-300-005Z
• Product Codes: A2C59506225
• Additional Numbers: 5WS40019, 5WS40018