CNG Components

Keihin Injectors

Injects CNG into the inlet manifold for each cylinder. Developed by Keihin Corp, Japan, one of the world’s leading injector manufacturers. Injectors are of OEM quality and reliability.

  • OEM quality injector.
  • Lifespan at least 290.000.000 cycles or 240.000 km -> 2 year unlimited warranty!
  • Excellent linear flow range (linear 2% accuracy form min to max flow). Linear flow starting from 2,5 msec.
  • Low-resistance 1,25 Ω.
  • 5 injector sizes for engine capacities from 9 kW till 45 kW each cylinder. (e.g. 3 cyl with 27 kW to 10 cyl. 450 kW).

Injector Rail

  • R67-01 & R110 homologatedPA6 Glassfiber “re in forced” nylon.
  • Only right version available. If required fitter has to transfer right version into left version.
  • High profile look.
  • Light weight and compact.
  • Uncomplicated fitting.
  • Assembled and leak tested at factory prior to dispatch.
  • 2, 3, 4 or 5 cylinder assemblies.

Fuel Switch

The fuel switch is operated by a touch key to switch from gasoline to CNG and vice-versa. The fuel switch is also equipped with LED indicators to monitor the level of the fuel in the tank. When the CNG level is too low the reserve LED lights up. When there is an automatic switch-over to gasoline because the CNG tank is empty, the driver is being warned by a buzzer signal and a flashing LED indicator.

The fuel switch used by the VSI-system controls the following functions:

  • Monitoring the fuel level.
  • Fuel Selection
  • Reporting errors.


Filter Unit

This device is filtering the fuel to prevent damage to the injectors. The filter unit is also equipped with a pressure/temperature sensor for the fuel.

  • Filter operates with a 0-4 bar pressure sensor.
  • PA6 Glassfiber “re-inforced” nylon.
  • Shorter filter replacement duration. Special glass fiber filter material [10ųm]. First replacement after 15,000 miles and subsequently every 30,000 miles thereafter.
  • Single and double outlet version.


The ECU (Electronic Control Unit) controls the VSI system.

  • Approval for CNG R110 regulations
  • 3 versions: 4, 8 and 10 cylinder
  • All upgrades are downwards compatible
  • High reliable
  • Measuring the engine signals, gasoline-injectors, rpm, MAP, coolant, etc.
  • Controlling the solenoids
  • Controlling the injectors
  • Cut off the gasoline-injectors
  • Read out fuel choice
  • Communication with the diagnostics program
  • ECU injector driver capability up to 10 cylinders
  • Injector drivers based on “closed loop peak & hold current control”
  • Constant monitoring of the injector diagnostics:
    Overload / Driver temperature / Short circuit / No load
  • Software for diagnostics, service and parameter load operates with Windows 98, 2000, XP and Vista
  • CAN-controller (2.0b) enables communication with OEM CAN-bus
  • Complete wiring harness: color coded, with text and numbers for simple and efficient installation

CNG Pressure Regulator


  • Precision built ‘Single Stage’ regulator developed by KEIHIN in cooperation with PRINS
  • Based on OEM technology, quality and standards
  • Integrated relief valve
  • Small pressure drop level equivalent to a two stage regulator
  • Manifold reference function
  • System pressure is not affected by tank pressure
  • Performance at cold temperature is identical as at normal temperature
  • Optional in-line electrical lock-off valve. Wide range of connections possible at the valve inlet