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.

Overview

This Siemens VDO injection pump (5WS40019) is designed for 2.0 HDi engines (RHR / RHK) producing around 100 kW. The unit is commonly fitted to a range of Stellantis vehicles (Citroën and Peugeot) and to certain Ford, Volvo and Mazda applications where the DW10 platform or compatible variants are used. This listing includes frequently searched part numbers such as 5WS40019, 5WS40809, 1920QH and 1920N8—useful when searching by product code.

Technical Information

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

Compatible Vehicles (Examples)

Typical vehicle models that use this pump include Citroën C4, Citroën C4 Picasso, Citroën C5 (including X7), Citroën C8, Peugeot 307, Peugeot 407 and Peugeot 807. Also fitted in certain Ford, Volvo and Mazda applications using compatible 2.0 HDi engine variants. Always verify engine code (RHR / RHK) when matching parts.

Function And Common Faults

The injection pump supplies high-pressure fuel to the common-rail system and precisely meters fuel to the injectors according to engine demand. Common failure modes include internal wear, contamination from degraded fuel or dirty filters, sticking or failing control valves/actuators, and external leaks. Symptoms of a failing pump are rough idle, loss of power, difficult cold starts, increased fuel consumption and fault codes related to fuel pressure or delivery.

Replacement Procedure (General Guidance)

Replacement of the injection pump should be carried out by a qualified technician. General steps include:

• Relieve fuel system pressure and isolate the battery supply for safety.
• Remove intake and ancillary components to access the pump.
• Mark and note timing alignment marks and drive position before removal.
• Disconnect fuel lines, electrical connectors and mounting bolts, then remove the pump.
• Install new pump ensuring correct timing alignment, torque settings and new sealing gaskets.
• Prime the fuel system, bleed air, then check for leaks and proper fuel pressure.
• Clear any related fault codes and verify engine operation under load.

Because timing and calibration are critical, calibration or adaptation may be required after installation—this work is best done with proper diagnostic and calibration equipment.

Installation Recommendations

• Perform the replacement in a clean environment to avoid introducing contaminants to the fuel system.
• Use new sealing washers, gaskets and properly rated fuel lines when reassembling.
• Follow manufacturer torque specifications for all fasteners and respect engine timing marks.
• Prime and bleed the fuel system thoroughly before attempting to start the engine to prevent damage to the pump and injectors.
• If available, use factory diagnostic tools to confirm fuel pressure, timing and to run any required adaptations.

Why This Part Most Often Fails

Failures are most commonly caused by contaminated fuel (water, particles, or degraded additives), insufficient fuel filtration, running with low fuel levels that reduces lubrication, or long-term mechanical wear. Electrical actuator failures and seal deterioration can also lead to loss of performance or leaks. Regular fuel filter maintenance and using good-quality diesel significantly extend pump life.

This high-pressure injection pump is designed for 2.0 HDi 100 kW turbo diesel engines (RHR / RHK) and features the SIEMENS VDO 5WS40019 platform. It supplies precisely metered diesel fuel to the common-rail system and integrates a pressure regulation function to maintain stable rail pressure under varying engine loads. The robust mechanical construction is suitable for workshop replacement and for experienced DIY mechanics familiar with diesel fuel systems.

Key Benefits

– Precise fuel delivery for stable idle, improved throttle response and fuel economy.
– Built with an integrated pressure regulator to ensure correct rail pressure.
– Direct fit for many Citroën and Peugeot applications using the 2.0 HDi 100 kW engines.

Compatibility and Typical Applications

Compatible with vehicles and engine families that use the 2.0 HDi 100 kW RHR / RHK pump, including (but not limited to):

Citroën: C4, C4 Picasso, C5, C5 X7, C8
Peugeot: 307, 407, 607, 807
Also fitted to certain Ford, Volvo and Mazda models that share the same diesel engine/pump specification.

Common Symptoms of a Failing Injection Pump

– Loss of power and poor acceleration.
– Hard starting or extended cranking time.
– Rough idle, misfires or intermittent stalling.
– Excessive smoke from the exhaust or fuel smell in the engine bay.
– Visible fuel leaks around the pump or fuel lines.
– Low rail pressure indicated by diagnostic trouble codes or reduced performance.

How Replacement Is Performed

Replacement of a high-pressure injection pump should be carried out by a qualified mechanic or an experienced DIY technician with access to the correct tools and workshop documentation. Typical steps include:

1. Depressurize the fuel system and remove any necessary engine covers.
2. Mark the engine timing positions and remove drive connections to the pump (camshaft gear, timing belt/chain interface as applicable).
3. Disconnect fuel lines and electrical connectors, catching any spilled diesel and replacing seals.
4. Remove the pump and install the replacement, using new sealing rings and correct torque values for fasteners.
5. Re-establish timing alignment according to the service manual, prime the fuel system and bleed air from the lines.
6. After installation, check for leaks, verify rail pressure and clear or monitor any engine fault codes.

Installation Recommendations

– Work from the official service manual or factory workshop data for exact timing and torque specs.
– Replace all sealing O-rings and copper crush washers when re-connecting fuel lines.
– Use a torque wrench on pump mounting bolts to the manufacturer’s specified values.
– Prime and bleed the fuel system thoroughly to avoid airlocks.
– Inspect and replace the fuel filter and any damaged fuel lines to prevent premature failure of the new pump.
– After fitment, monitor rail pressure and engine operation; some systems may require fine adjustment or verification with a diagnostic tool to ensure fault-free operation.

Why This Part Most Often Fails

– Contaminated fuel (water, dirt, or varnish) causing accelerated wear of internal components.
– Neglected maintenance such as overdue fuel filter changes leading to abrasive wear.
– Poor lubrication resulting from fuel contamination or long periods of idling.
– Internal mechanical wear of rotors, vanes or bearings after high mileage.
– Fuel leaks or air ingress causing loss of rail pressure and cavitation damage.

Technical Information

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

Final Notes

This pump is a precision diesel component. For reliable and long-term operation, use clean diesel fuel, observe recommended service intervals (fuel filter replacement) and follow correct installation and priming procedures. If in doubt about timing or priming steps, seek professional assistance with the appropriate workshop tooling and diagnostic equipment.

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