Fuel Injector Balance Test With Special Tool: Description
WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. 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 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. See Fig 1. See FUEL INJECTOR BALANCE TEST EXAMPLE (TYPICAL) .
FUEL INJECTOR BALANCE TEST EXAMPLE (TYPICAL)
| Condition | Cylinder No. 1 | Cylinder No. 2 | Cylinder No. 3 | Cylinder No. 4 |
| 1st Reading | 43 psi (296 kPa) | 43 psi (296 kPa) | 43 psi (296 kPa) | 43 psi (296 kPa) |
| 2nd Reading | 19 psi (113 kPa) | 17 psi (117 kPa) | 18 psi (124 kPa) | 21 psi (145 kPa) |
| Amount Of Drop | 24 psi (165 kPa) | 26 psi (179 kPa) | 25 psi (172 kPa) | 22 psi (151 kPa) |
| Average Range: 22.5-25.5 psi (156-176 kPa) | Injector Okay | Replace Fuel Injector, Too Much Fuel Pressure Drop | Injector Okay | Replace Fuel Injector, Too Little Fuel Pressure Drop |