Fuel Injector Ultrasonic Cleaning & Flow Testing
Mooresville North Carolina

Fuel Injector Anatomy

  1. Fuel filter basket – The fuel filter basket prevents debris from clogging the pintle and seat. Just a second line of defense, the inline fuel filter does the real filtering.
  2. Electrical Connection – The EFI (Electric Fuel Injector) is connected to the on-board computer through the electrical connection. The precise amount of fuel to be injected is calculated to give the best performance, provided your injectors are clean and balanced.
  3. Injector body – The injector body, shown in cut-away view to the left, is the case that holds the internal parts in place. This is a sealed unit and parts inside cannot be replaced. Only the o-rings, pintle cap, and filter can be replaced on the injector body. Beware of people that claim to “Rebuild” them. This is a misleading claim.
  4. Return Spring – The Return Spring pushes on the solenoid and re-seats the pintle when current is removed from the coil, thereby stopping fuel flow.
  5. Solenoid – The Solenoid moves in response to the electrical field generated in the coil windings to pull the pintle away from the seat, allowing fuel to pass in exactly the right amount.
  6. Pintle – The Pintle is a finely machined part that normally sits down on the seat to prevent fuel from passing through the injector. When lifted away from the seat, the fuel is allowed to pass. The pintle usually only moves a few thousands of an inch. This is why it is important to keep fuel system cleaned and maintained.
  7. Pintle seat & cap – The Pintle Seat is a precision machined surface that is matched to the pintle. The design and size of the seat and pintle determines the spray pattern and flow rates. The Pintle Cap holds the lower o-ring in place and insulates the seat from the engine heat. It also protects the pintle from damage while the injector is removed.


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