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Support for your FT20 Unit.


The "Minimum Installation" is a good way to start getting acquainted with your Fuel Tuner. It is quick, requires very few tools but does not allow you to enjoy the full potential of the product. The Fuel Tuner (FT for short), can do so much more, and its power and the benefits to you are unleashed when you connect a few more wires (see the section on the Full Installation).





This installation is the absolute minimum and will provide you with a "One Dimensional" map with 24-RPM sites spread over the calibrated RPM range. The number of sites on a map is an indication of the amount of tuning that can be done for specific area, in this case RPM.





The Minimum Installation has been broken down into 6 (six) practical steps, with photos. These steps cover the installation of the unit into the vehicle and the unit is not connected to a computer. Once the physical installation has been completed the engine will run as before. For the purpose of tuning the engine you need to consult the LetRipp Software Guide.


This manual covers all aspects of the PC (Laptop) operation.





FT20 Fuel Tuner - Finding a Suitable Location To Mount or Install The Unit

Find a suitable location for the unit, i.e. :

  • Away (or shielded) from hot surfaces
  • Within harness reach of the injectors and the vehicle's ECU (Engine Control Unit)
  • Protected from water, water spray, or high pressure water cleaning. This is because the unit is not water-resistant or water-proof.
  • If possible, in a ventilated area.


The ideal location would be as close as possible to the battery of the vehicle, in the engine bay. This is the coolest place in the engine. However, you would need to seal the unit in a plastic bag to ensure that it would not get wet.


The unit does not have to be clamped down, but should not rattle. The housing is insulated, but should not touch any live wires, except the chassis. Once the tuning is complete, the unit can be packaged into a plastic bag and sealed, and left in the suitable location.





FT20 Fuel Tuner - Locating The Injectors of the Engine

Look around the vehicle's engine and locate the injectors of the fuel injected petrol engine.


Connect the loose wire (ground) of the injector harness(es) of the injector harness(es) to a suitable place on the metallic chassis. This is to GROUND the unit.





FT20 Fuel Tuner - Connecting the Plug-and-Play Injector Harness

Remove the existing injector caps/plugs, by unclipping them. As shown in the photo.


FT20 Fuel Tuner - Connecting the Plug-and-Play Injector Harness

Using the plug-and-play harness(es) supplied with the FT kit, connect the injector harness to the injectors (if you are installing on a 4-cylinder engine, you'll have two sets of plug-and-play injector harnesses. As shown in the photo.


FT20 Fuel Tuner - Connecting the Plug-and-Play Injector Harness

The photograph shows the injector plug of the engine and the harness injector clip.





FT20 Fuel Tuner - Connecting The Ground Wires

Connect the ground wire(s) to a suitable metallic place on the chassis. In the photo, there were two screws in the chassis, which made it easy to attach the lugs to the chassis.


Note : If there is no metallic section exposed on your vehicle's chassis, you may need to scratch some of the paint off to expose the metal.





FT20 Fuel Tuner - Connecting The Harness To The Unit

Connect the connector plugs from the harness to the matching connector to the unit.
As shown in the photo.





A very important Step in the Minimum Installation is ensuring that you have the Injector Harness connected correctly to the injectors of the engine. The injectors can be wired in two ways, and therefore we have supplied a "reversing" plug, which will recognize the different wiring that vehicle manufacturers use. You will need to determine whether your particular engine will need to make us of the special "reversing" plug. There is a "reversing" plug per connector on each injector harness. You will notice that the "reversing" plug patches the wire colours of the relevant part of the injector harness.


FT20 Fuel Tuner - Finding The Injector Wiring Polarity

You will know when your installation requires the use of the "reversing" plug when you do not get a green LED, after the injector harnesses have been connected. You will need to do a test, on one of the injector harnesses, to confirm the need for the "reversing" plug.


To test the wiring of the injector harness #1 :

  • Identify the harness #1 (it will be marked with a yellow tab on the wiring). It is the one closest to the LED lights. Use only one pair of injector connectors at the end of it.
  • Connect the ground lead/wire to a suitable place on the chassis.
  • Connect harness #1 to cylinder #1, and the connector to the Fuel Tuner connector, without the "reversing" plug.
  • Start your engine, and observe that the Green LED flashes, and the Red LED is off.
  • If this is not the case, switch off the engine.
  • Insert the applicable reversing plug (matching wire colour), and try again.


Usually all injectors are wired in a consistent fashion. If you would like to confirm this, you can then repeat the steps above for each cylinder.

Note : The Fuel Tuner unit receives power from harness #1 (close to the LED) and  from the GROUND wire you have connected to the chassis. It then tests that the injector is "pulsed" and indicates this on the GREEN LED.






The Fuel Tuner plug-and-play injector harness has been manufactured to clip onto Bosch injectors. If you find that your vehicle does not have Bosch injectors, you will need to replace the Bosch injector clips on the Fuel Tuner plug-and-play harness, with the applicable injector clips for the injectors in your vehicle.



To replace the injector clips on the Fuel Tuner plug-and-play harness, follow the steps below :


  • Confirm which type of injectors you have in your vehicle, for example, Delphi injectors.
  • Source the injector clips that will fit onto your type of injectors.
  • Cut off the Bosch injector clips off the Fuel Tuner's plug-and-play harness.
  • Connect the new injector clip wires to the wires of the Fuel Tuner plug-and-play harness in the SAME PIN ORDER of the injector clips, and follow this order for each injector.
  • This means that pin 1 on the harness MUST BE MATCHED to pin 1 of the injector clip wire. See below for an example of a Bosch injector and a Delphi injector and the matching of wires.


FT20 Fuel Tuner - Adapting The Plug-and-Play Injector Harness