System Description
WARNING: This page is about a different car, the 2004 GMC Sierra and 2004 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The scan tool is first used to energize the fuel pump relay. The scan tool 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 |