Type 25 Fuel Injector Set - Waterboxer Engines

As the decades roll on, the original fuel injectors fitted to Waterboxer engines inevitably suffer from wear and contamination. Dirt and debris from ageing fuel tanks damage the injector pintles, hose nipples become scratched, plastic ends grow brittle and crack, and—most critically—the injectors drift out of balance with one another. The result is uneven fuelling, rough idle, poor throttle response and disappointing fuel economy.

These brand-new, modern replacement fuel injectors are designed to completely eliminate those problems.

Unlike the original Bosch injectors, these units are built to a much tighter overall flow-rate tolerance, using multi-point dynamic flow testing. Even more importantly, each kit is supplied as a matched set of four, with all injectors flowing within ±1% of each other across all operating ranges. This means every cylinder receives the same precise amount of fuel, whether you’re idling in traffic or pulling hard up a hill.

The result is smoother running, improved throttle response, better fuel economy and increased long-term reliability—exactly what a tired Waterboxer needs if a standard tune-up hasn’t cured sluggishness or uneven running.

How it works

Fuel injectors meter and atomise fuel into each intake runner. When injectors age, inconsistent spray patterns and uneven flow cause cylinders to run rich or lean relative to one another. These modern injectors restore precise, even fuel delivery, ensuring clean combustion and balanced engine performance across all cylinders.

What’s included

This is a complete ready-to-install kit, supplied with all wear components already fitted:

• 4 × Brand-new fuel injectors (matched set)

• 4 × Quality NBR fuel hoses, pre-installed

• Stainless steel ear clamps fitted to each hose

• 4 × Small end injector seals

• 4 × Large end injector grommets

Important installation notes

• The retaining ring design differs slightly from the original OE injectors

• When fitting, ensure the inner lip of the large injector grommet fully seats into the injector body to securely retain the injector

• Electrical plug caution: The Bosch-style connector is shared with other nearby engine components

  • Always unplug and reconnect one connector at a time

  • Label plugs if removing multiple connections (for example during engine or throttle body work)

Fitment notes

• Suitable for Right Hand Drive models (driver’s side = right, passenger side = left)

• Direct replacement for original Waterboxer injectors

• Ideal upgrade for engines with rough idle, hesitation, or poor fuel economy

Fitment

• Engine types: All Waterboxer petrol engines

• Engine codes: Including MV and DJ

• Model years: 1983–1991

Applications

• VW Type 25 / T3 / Vanagon – 1.9 & 2.1 Waterboxer (1983–1991)

May also be required (sold separately)

• Fuel pressure regulator (recommended on high-mileage engines)

• Fuel filter

• Injector wiring plug repair connectors (if originals are brittle)