Injector Testing


Any fuel system requires cleaning, an EFI system requires filters capable of 30 micron, this is not used in speedway, and refueling at the race track using funnels and drums certainly does not assist the situation. Some cars are experiencing small balls of rubber out to the fuel bladder that is also blocking the fuel injectors.


This is designed to operate with a detergent solution you can purchase, I have found that this reacts with the VN Injectors we are using and causes corrosion, I am using Kero, this is compatible with methanol and leaves an oily film in the injector when finished.

When cleaning the Injectors remove the filter basket and clean for 20 minutes, the injectors need to be pulsed when in the bath.

If using Kero make sure the temperature of the solution does not rise too high.




The Sonic Bath can be used to clean:

  • Sprint Car Injectors
  • Fuel Filter Elements
  • Jewellery, recommended to change to water first
  • Carby Parts



This is designed to simulate operating on the race track and used to provide comparison of different injectors, a typical VN injector will flow 105cc in 30 seconds, any reading more than 10% either side of that will require further attention.



A fuel system with a VL fuel pump as used on the race car, for the fuel rail use half of a VP/VR fuel rail, it must incorporate the pressure regulating valve.

Use plastic measuring cups for measuring the flow.

If using a 12 volt battery make sure it is charged as it is possible to still get the correct pressure but not the correct flow with a battery with less than 12 volts.

For a fuel tank a large Go Kart tank makes an ideal one, and put a pressure gauge in the line if you have one.



  • Remove the filter basket
  • If a standard injector remove the end cap and std disc, if it is a racing one leave it together
  • If they are injectors you are racing with test them first to see the difference.
  • Plug one injector at a time into the Injector Tester and determine if it is operating and the AMP load is not excessive, if the Amp load is excessive the fuse will blow to protect the unit, if this happens replace the injector.
  • Connect up to three injectors at a time and place in the Sonic Bath, turning both the Injector Tester and Sonic Bath on for 20 minutes.
  • Remove the Injectors from the wires, then with one injector at a time connected to the Injector Tester reverse flush with compressed air.
  • Place the Injectors in the stand you have made and test them
    • With the fuel pump operating check to see that there is no leaks on the injector casing
    • Flow test the injectors for 30 seconds.