Fuel Injection / Collection Rail

Domed Cap Nut – Fuel Pump & Fuel Rail Fixing M12 x 15,5

High-quality domed cap nut designed for securing components within the Porsche fuel system, including the fuel pump and fuel rail assemblies.

Used across a wide range of models including Porsche 924S, 944, 968, 928, and 964, this cap nut provides a secure fastening solution while protecting exposed threads with its domed design. It plays an important role in maintaining the integrity and safety of fuel system connections.

Fits:

• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-91
• Porsche 928GTS 5.4L 1992-95

Diagram ref no 38

Manufactured to OEM specifications, this component ensures precise fitment, corrosion resistance, and long-term durability—making it ideal for maintenance, repair, or restoration work.

Reference Number: 92811047505

Key Features

• Domed cap nut for fuel system applications
• Used on fuel pump and fuel rail assemblies
• Suitable for multiple Porsche models
• Protects threads while securing components
• OEM-style fit and finish
• Durable, corrosion-resistant construction

Function and Purpose

This cap nut is a key fastening component within the fuel system.

It helps to:

• Secure fuel pump and fuel rail components
• Protect threaded studs from damage and corrosion
• Maintain safe and stable fuel system assembly
• Ensure proper sealing and fastening integrity

Why Replace Cap Nuts

Over time, hardware components can degrade or become damaged.

Common issues include:

• Corrosion or rust
• Rounded or damaged threads
• Loss of proper torque retention
• Compromised fastening security

Replacing worn hardware ensures reliable and safe system assembly.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

92811047505

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Fuel line - runs from the fuel rail to the diaphragm damper
This original Porsche fuel line forms part of the engine fuel delivery system and is used to connect the fuel rail to the diaphragm damper, helping maintain correct fuel flow and pressure control.

Fits:
Porsche 924 S 2.5L 1986 - 1988

Porsche 944-2 2.5L 1985 - 1988
Porsche 944 2.7L 1989 

Porsche 944 Turbo 2.5L 1986 - 1991
Porsche 944 Turbo S 2.5L 1988 

Diagram ref. 11

It is designed as the fuel line running from the fuel rail to the diaphragm damper on selected Porsche 924S and 944 models. This part is used in the fuel injection system and connects key fuel delivery components in the engine bay.

This part cross-references with earlier Porsche number: 94411041302

Functions
• Connects the fuel rail to the diaphragm damper
• Carries fuel within the engine fuel injection system
• Helps maintain correct fuel delivery to the fuel rail system
• Supports proper fuel pressure damping and fuel system stability
• Provides a factory-correct fuel line route and connection
• Helps reduce fuel pulsation when used with the correct diaphragm damper
• Replaces an aged, cracked, leaking or damaged original fuel line
• Maintains OE Porsche fitment and fuel system specification.

Why Replace This Part?
Fuel lines are exposed to fuel pressure, engine-bay heat, vibration and age-related deterioration. Over time, the original line can harden, crack, seep fuel or deteriorate at the fittings. Because this line carries fuel in the engine bay, any sign of leakage or fuel smell should be inspected immediately. Replacing the old line with a Genuine Porsche OE fuel line helps restore the correct connection between the fuel rail and diaphragm damper, supporting safe fuel delivery and original Porsche fuel system reliability.

When to Replace This Part
•  If there is a fuel smell in the engine bay
•  If the line is cracked, brittle, swollen or visibly damaged
•  If fuel is seeping or leaking from the hose or fittings
•  During fuel rail, diaphragm damper or fuel pressure system repairs
•  During fuel injection system restoration or preventative maintenance
•  If fittings are corroded, seized or damaged
•  When replacing old, non-original or incorrectly routed fuel hose
•  Before recommissioning a stored Porsche 924S or 944.

Where It Fits on the Car
This fuel line fits in the engine bay fuel injection system, running between the fuel rail and the diaphragm damper. It is shown in Porsche fuel injection / collection rail diagrams and is commonly identified as the fuel line from the fuel rail to the diaphragm damper. 

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

94411041303

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Fuel line - runs from the fuel rail to the diaphragm damper
This OE Match fuel line is a replacement fuel system hose/pipe used between the fuel rail and diaphragm damper on Porsche 924S, 944 2.5L / 2.7L, and 944 Turbo models from 1985 to 1991. It is designed to match the original-style fitment and function, helping restore safe and reliable fuel delivery.

Fits:
Porsche 924 S 2.5L 1986 - 1988

Porsche 944-2 2.5L 1985 - 1988
Porsche 944 2.7L 1989 

Porsche 944 Turbo 2.5L 1986 - 1991
Porsche 944 Turbo S 2.5L 1988 

Diagram ref. 11

The fuel line connects the fuel rail to the diaphragm damper within the fuel injection system. The diaphragm damper helps smooth pressure pulses in the fuel circuit, while the line carries fuel securely between the connected components to support stable fuel pressure and consistent engine running.

This part cross-references with earlier Porsche number: 94411041302

Functions
• Connects the fuel rail to the diaphragm damper
•  Carries fuel through the injection system
•  Supports stable fuel pressure delivery
•  Helps reduce fuel pressure pulsation through the damper circuit
•  Replaces aged, leaking, cracked, or damaged original fuel lines
•  Helps restore safe fuel system sealing
•  OE Match replacement for Porsche fuel system repair or restoration.

Why Replace This Part?
Fuel lines can deteriorate over time due to fuel exposure, heat, pressure, vibration, and age. The hose or pipework can crack, harden, seep, corrode, or leak, while fittings may become worn or seized. A damaged fuel line can cause fuel smell, fuel pressure loss, poor running, starting issues, or unsafe fuel leakage. Replacing the line helps restore fuel system safety, correct fuel pressure control, and reliable engine performance.

When to Replace This Part
•  The fuel line is cracked, leaking, perished, corroded, or damaged
•  Fuel smell or seepage is present in the engine bay
•  The fittings or unions are worn, seized, or heavily corroded
•  Fuel pressure instability or poor running is suspected
•  The fuel rail or diaphragm damper is being replaced
•  The fuel injection system is being serviced or recommissioned
•  The vehicle is undergoing Porsche 924S or 944 fuel system restoration.

Where it fits on the car
This fuel line fits within the engine bay fuel injection pipework, connecting the fuel rail to the diaphragm damper. It forms part of the fuel pressure control circuit and should be installed according to the factory fuel system routing.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

94411041303

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Rennline High Pressure Fuel Rail 
Upgrade your aging factory fuel system with Rennline’s High Pressure Fuel Rail Line. Designed to outperform and outlast the original, this premium replacement features a modern braided fuel line paired with precision CNC-machined billet aluminum ends, ensuring a secure, leak-free fit. Unlike other aftermarket options, this rail follows the OEM routing to prevent interference with the rocker cover. Perfect for stock replacements or high-performance builds.

Fits:

• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988>>

Diagram ref no 11 

Key Features:

• Modern braided fuel hose for enhanced durability and higher pressure tolerance
• CNC-machined billet ends for an OEM+ look and performance
• Includes 10mm & 8mm to -6 JIC compression fittings
• Ideal for both factory replacement and performance applications

What the Product Does

• Delivers high-pressure fuel reliably to the injectors.
• Withstands higher fuel system pressures compared to aging OEM parts.
• Prevents leaks with precision-machined fittings and modern hose construction.
• Maintains factory routing for a clean, interference-free fit.

Symptoms of a Failing or Worn Fuel Rail

• Strong fuel smell from the engine bay.
• Visible leaks or damp spots on the fuel line/rail. 
• Hard starting or poor performance under load.
• Fuel pressure loss or misfires.
• Cracked or brittle factory lines due to age. 

Common Reasons for Failure

• Aging Materials: Original rubber fuel lines harden and crack over time.
  
• Heat Exposure: Constant engine bay heat accelerates degradation.
  
• Fuel Pressure Stress: Stock parts may struggle with modern fuel blends and higher pressures.
  
• Corrosion: Factory metal ends may rust or weaken.

Why Replace?

• Prevents dangerous fuel leaks and fire hazards.
• Restores reliable fuel delivery and performance.
• Provides a long-term solution with modern materials.
  
• Supports both daily driving and high-performance builds.
• Eliminates common clearance issues with poorly designed aftermarket options.

 Ideal For: Porsche 924S, 944, and 951 owners seeking a safe, reliable upgrade to their fuel delivery system - whether for everyday driving or high-performance tuning.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

M141

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