Fuel Injector Balance Test

CIRCUIT DESCRIPTION
The Fuel Injector Tester J 39021-301 and the injector switch box J 39021-210 energize the injector for a precise amount of time allowing a measured amount of fuel into the manifold. This causes a drop in fuel rail pressure that can be recorded and used to compare each injector. All injectors should have the same pressure drop 10 kPa (15 psi).

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.

2. This step checks for the proper fuel pressure.
3. This step check for a decrease in the fuel pressure after the energizing each injector.