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Home >> Saturn >> 2003 >> LW200 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Fuel Systems >> Fuel Injector Balance Test With Special Tool >> System Description
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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. See FUEL INJECTOR BALANCE TEST WITH SPECIAL TOOL EXAMPLE (TYPICAL)  .

FUEL INJECTOR BALANCE TEST WITH SPECIAL TOOL EXAMPLE (TYPICAL)

Condition Cylinder No. 1 Cylinder No. 2 Cylinder No. 3 Cylinder No. 4
1st Reading 55 psi (379 kPa) 55 psi (379 kPa) 55 psi (379 kPa) 55 psi (379 kPa)
2nd Reading 42 psi (290 kPa) 45 psi (310 kPa) 48 psi (331 kPa) 46 psi (317 kPa)
Amount Of Drop 13 psi (89 kPa) 10 psi (69 kPa) 7 psi (48 kPa) 9 psi (62 kPa)
Average Range: 8-11 psi (57-77 kPa) Replace Fuel Injector - Too Much Fuel Pressure Drop Injector Okay Replace Fuel Injector - Too Little Fuel Pressure Drop Injector Okay