DO NOT REPLACE YET
Resistance alone is not an injector verdict
An injector can pass an electrical check and still have a mechanical flow or sealing problem. Use the balance test when the complaint requires flow comparison.
LS1 · 2002 · FUEL INJECTION
2002 LS1 Injector Balance — Electrical Pass ≠ Flow Proven
2002 LS1 injector diagnosis using pressure-drop comparison so an electrical pass is not mistaken for proof of correct fuel flow.
APPLICATION: 2002 Firebird / Formula / Trans Am 5.7L LS1. The pressure-drop comparison is procedure-specific.
Control hot-soak error
The factory procedure requires coolant temperature below normal operating temperature so hot-soak fuel boiling does not corrupt the pressure readings.
Factory comparison rule
If each injector's pressure drop is within 1.5 psi (10 kPa) of the average pressure drop, the injectors are flowing evenly under this test.
Use the result correctly
- Verify base fuel pressure is correct and stable before comparing injectors.
- Record the first and second pressure for every injector.
- Calculate each injector's pressure drop.
- Calculate the average drop and compare every injector to it.
- A failed comparison isolates a flow imbalance; it does not by itself explain why that injector is abnormal.
Modified-car checkpoint
Injector size, rail/manifold fitment, actual fuel pressure and calibration data all matter on modified cars. An injector advertised by lb/hr or cc/min alone does not prove the calibration matches the hardware.
AFTER THE FAILURE IS PROVEN
Use the proven failed branch—not the original symptom—to choose the replacement. Go from diagnosis to the Parts Verdict →