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Porsche // 996 (911) (1997-2005) // Any
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- 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 924 2.0L 1980-85
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- 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 928S2 4.7L 1984-86
The Genuine Porsche Threaded Sleeve (Part Number: 91160931000) is a small but important electrical connection component used within the ignition lead and spark plug connector assemblies of selected classic Porsche models.
Sold Each.
x4 Required Per Car.
Fits:
- 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 924 2.0L 1980-85
- Porsche 924S 2.5L 1986-87
- Porsche 924S 2.5L 1988
- Porsche 944 2.5L 8V 1982-87
- 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 928S2 4.7L 1984-86
Diagram Ref No 28
Manufactured as an original equipment Porsche replacement part, this threaded sleeve provides a mechanical and electrical connection within the high-voltage ignition cable assembly.
It is associated with the spark plug connector and ignition lead termination, helping maintain a secure connection so that ignition voltage can pass through the lead assembly towards the spark plug.
The component is listed in Porsche's engine electrical and ignition system diagrams for several classic models, including the Porsche 924, 928, 944, 964 and 993.
Although small in size, the threaded sleeve plays a useful role in maintaining the integrity of the ignition lead connection.
The ignition system must deliver high-voltage electrical pulses reliably from the ignition source to the spark plugs. Any weakness in the electrical connections can increase resistance, interrupt current flow or contribute to intermittent ignition performance.
Over time, the threaded sleeve may become damaged through corrosion, repeated removal, incorrect installation or deterioration of the surrounding ignition lead components.
A damaged or loose connection may contribute to poor ignition performance, particularly when the engine is operating under load or in damp conditions.
Replacing a worn or defective threaded sleeve with a Genuine Porsche component helps restore a secure ignition lead connection, maintain electrical continuity and support reliable engine operation.
This part is particularly relevant during spark plug lead repairs, ignition connector replacement, engine servicing and classic Porsche restoration projects.
What This Product Does:
The threaded sleeve is an electrical connector component used within the ignition lead assembly.
Its primary function is to provide a threaded mechanical connection and conductive interface between compatible ignition cable and spark plug connector components.
During engine operation, the ignition system generates high-voltage electrical pulses that travel through the ignition leads to the spark plugs.
These pulses must pass through secure electrical connections before reaching the spark plug electrodes.
A properly fitted threaded sleeve helps maintain a reliable connection within the ignition lead termination.
Its main functions include:
- Connecting ignition components: Provides the appropriate threaded connection within the ignition lead and spark plug connector assembly.
- Maintaining electrical continuity: Helps establish a conductive path for ignition voltage.
- Securing the ignition lead connection: Supports correct attachment of compatible cable-end components.
- Supporting spark plug operation: Helps ensure high-voltage pulses reach the spark plug through the intended connection.
- Maintaining connector integrity: Reduces the likelihood of unwanted movement within the correctly assembled connection.
- Supporting reliable ignition performance: Helps prevent interruptions caused by a loose or damaged electrical contact.
- Preserving original ignition lead construction: Maintains the factory-specified connector arrangement.
- Supporting ignition cable repairs: Allows an individual connection component to be replaced where the surrounding lead remains serviceable.
- Maintaining compatibility with the original connector: Provides the specified connection interface for applicable Porsche ignition assemblies.
- Supporting long-term electrical reliability: Helps preserve a secure mechanical and electrical connection.
Symptoms Of Wear Or Failure:
The threaded sleeve is a relatively simple component without moving parts, but its condition can affect the quality of the ignition lead connection.
Ageing, corrosion, mechanical damage or repeated removal may weaken the threaded or conductive surfaces.
Common symptoms of a worn or damaged threaded sleeve include:
- Intermittent engine misfire: An unreliable electrical connection may occasionally interrupt ignition voltage delivery.
- Rough engine idle: Poor ignition continuity may contribute to uneven combustion.
- Hesitation during acceleration: An intermittent ignition connection may become more noticeable under engine load.
- Reduced engine responsiveness: Weak or inconsistent ignition performance may affect throttle response.
- Difficult starting: A severely compromised connection may prevent the affected spark plug from firing consistently.
- Loose spark plug connector: Damaged threads may prevent the connector assembly from fastening securely.
- Corroded metal surfaces: Oxidation may compromise the electrical contact.
- Damaged or stripped threads: Mechanical damage may prevent correct assembly.
- Visible connector deterioration: Wear or deformation may become apparent during ignition lead inspection.
- Intermittent electrical continuity: Resistance measurements may reveal an unstable connection when the assembly is moved.
- Increased electrical resistance: Poor contact may add resistance to the ignition circuit.
- Engine misfire in damp conditions: Moisture can aggravate weaknesses in already deteriorated ignition components.
- Connector separation during servicing: A damaged sleeve may no longer retain the associated parts correctly.
- Poor ignition lead fitment: The connector may not seat or assemble as intended.
- Repeated ignition problems after plug replacement: A defective ignition lead connection may remain faulty even when the spark plug is new.
Why Replacement Matters:
Replacing a defective threaded sleeve helps maintain the integrity of the ignition lead assembly.
A loose, corroded or damaged sleeve may prevent the ignition cable and spark plug connector from forming a reliable connection.
If the connection becomes intermittent, ignition voltage may not reach the spark plug consistently, potentially causing rough running, hesitation or misfires.
Continued operation with an unreliable ignition connection can also make fault diagnosis more difficult, especially on older vehicles with multiple ageing ignition components.
Installing a Genuine Porsche replacement Threaded Sleeve helps to:
- Restore secure ignition lead attachment: Replace damaged or worn threaded connections.
- Maintain electrical continuity: Help ensure reliable transfer of ignition voltage through the connector assembly.
- Reduce intermittent ignition faults: Address poor contact caused by a confirmed defective sleeve.
- Support smooth engine operation: Help restore consistent ignition performance where connector damage is responsible.
- Improve starting reliability: Address starting difficulties related to an unreliable ignition lead connection.
- Prevent connector loosening: Restore the intended mechanical retention of the associated components.
- Replace corroded electrical contacts: Renew a conductive connection affected by deterioration.
- Support ignition lead refurbishment: Replace an individual damaged part without unnecessarily changing unrelated components.
- Preserve the original ignition design: Maintain Porsche's specified connection arrangement.
- Support preventative maintenance: Address visible connector deterioration before complete failure occurs.
- Help maintain engine reliability: Restore the intended ignition connection when the surrounding assembly remains serviceable.
- Support classic Porsche restoration: Provide a Genuine Porsche component for original-style ignition system repairs.
Replacement is recommended when the sleeve is visibly corroded, has damaged threads, cannot be securely fitted or fails an appropriate electrical continuity inspection.
Where the ignition cable or spark plug connector is also damaged, replacing the sleeve alone may not provide a complete repair.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91160931000
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