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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1469 (Engine Control System - 4.8L, 5.3L, & 6.0L - Troubleshooting & Diagnosis) >> Diagnostic Information & Procedures >> Fuel Injector Balance Test with Special Tool >> Description >> Notes

Fuel Injector Balance Test with Special Tool: Description: Notes

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The scan tool is first used to energize the fuel pump. 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.

Fig 1: Performing Fuel Injector Balance Test With Special Tool
GM17713Courtesy of GENERAL MOTORS CORP.
Callout Component Name
1 First Fuel Pressure Gage Reading
2 Second Fuel Pressure Gage Reading
Fuel Injector Balance Test Example (Typical)

Cylinder 1 2 3 4
1st Reading 296 kPa (43 psi) 296 kPa (43 psi) 296 kPa (43 psi) 296 kPa (43 psi)
2nd Reading 131 kPa (19 psi) 117 kPa (17 psi) 124 kPa (18 psi) 145 kPa (21 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