Circuit Description: Notes
The scan tool first energizes the fuel pump and then the injectors for a precise amount of time allowing a measured amount of fuel into the manifold. This causes a drop in system fuel pressure that can be recorded and used to compare each injector.
Fuel Injector Balance Test Example (Actual Results May Vary)
| Cylinder | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| 1st Reading | 379 kPa (55 psi) | 379 kPa (55 psi) | 379 kPa (55 psi) | 379 kPa (55 psi) |
| 2nd Reading | 280 kPa (41 psi) | 310 kPa (45 psi) | 340 kPa (49 psi) | 317 kPa (46 psi) |
| Amount of Drop | 99 kPa (14 psi) | 69 kPa (10 psi) | 39 kPa (6 psi) | 62 kPa (9 psi) |
| Average Range: 47-87 kPa (6.8-12.6 psi) | Replace fuel injector - too much fuel pressure drop | Injector OK | Replace fuel injector - too little fuel pressure drop | Injector OK |