System Description: Notes
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 | 379 kPa (55 psi) | 379 kPa (55 psi) | 379 kPa (55 psi) | 379 kPa (55 psi) |
| 2nd Reading | 214 kPa (31 psi) | 200 kPa (29 psi) | 207 kPa (30 psi) | 228 kPa (33 psi) |
| Amount of Drop | 165 kPa (24 psi) | 179 kPa (26 psi) | 172 kPa (25 psi) | 151 kPa (22 psi) |
| Average Range: 156-176 kPa (22.5-25.5 psi) | Injector OK | Replace fuel injector - too much fuel pressure drop | Injector OK | Replace fuel injector - too little fuel pressure drop |