Pre-heat Hose MFI Fuel Pump. Porsche 911 1969-76 MFI  ❭  00004320521

MFI Pump Pre-Heat Hose - 25 x 440mm 

High-quality pre-heat hose with 25x440mm dimensions, designed for Porsche models equipped with Mechanical Fuel Injection (MFI) systems.

This hose connects the pre-heating circuit to the MFI pump, ensuring proper temperature regulation of the intake air and fuel system. Maintaining correct operating temperature is critical for smooth engine running, especially during cold starts and warm-up phases.

Fits:

• Porsche 911 1969-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1976 2.7L Carrera

Diagram ref no 39  

Manufactured to OEM specifications, this hose provides durability, flexibility, and resistance to engine bay heat, making it ideal for maintenance, repair, or restoration of classic Porsche MFI systems.

Key Features

• 25mm diameter, 440mm length pre-heat hose
• Suitable for Porsche MFI (Mechanical Fuel Injection) systems
• Part number 00004320521
• Designed for intake pre-heating circuits
• Supports proper engine warm-up operation
• Resistant to heat and engine bay conditions
• OEM-style fit and performance

Function and Purpose

This hose is an essential part of the MFI system.

It helps to:
• Deliver warm air to the MFI pump system
• Regulate intake and fuel system temperature
• Improve cold start performance
• Maintain stable engine running during warm-up
• Support efficient fuel injection operation

Why Replace Pre-Heat Hoses

Over time, pre-heat hoses degrade due to heat exposure.

Common issues include:
• Cracking or splitting
• Air leaks reducing system efficiency
• Hardening and reduced flexibility
• Poor cold start and warm-up performance

Replacing worn hoses ensures proper system operation and engine reliability.

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Related, superseded, cross reference or alternative numbers for comparison.

00004320521

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