System Description
The scan tool is first used to energize the fuel pump relay. The fuel injector tester is then used to pulse each injector 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 (Typical)
| Cylinder | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| 1st Reading | 393 kPa (57 psi) | 393 kPa (57 psi) | 393 kPa (57 psi) | 393 kPa (57 psi) |
| 2nd Reading | 310 kPa (45 psi) | 296 kPa (43 psi) | 303 kPa (44 psi) | 324 kPa (47 psi) |
| Amount of Drop | 83 kPa (12 psi) | 97 kPa (14 psi) | 90 kPa (13 psi) | 69 kPa (10 psi) |
| Average Range: 75-95 kPa (10.9-13.8 psi) | Injector OK | Replace fuel injector - too much fuel pressure drop | Injector OK | Replace fuel injector - too little fuel pressure drop |