Fuel Injector Balance Test With Tech 2

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

CIRCUIT DESCRIPTION
The scan tool first energizes the fuel pump and then the injectors for a precise amount of time allowing a measured amount of fuel into the manifold. This causes a drop in the fuel pressure that can be recorded and used to compare each injector.

TEST DESCRIPTION
3. The engine coolant temperature must be less than the operating temperature in order to avoid irregular fuel pressure readings due to Hot Soak fuel boiling.
4. The fuel pressure should be within the specified range with the fuel pump running. If the fuel pressure is not within the specified range, go to Fuel System Diagnosis. Component Tests and General Diagnostics
5. Allow the fuel pressure to stabilize about 3 minutes. On a hot vehicle the fuel pressure may increase due to fuel expansion after the pump stops running. This is a normal condition but the fuel pressure should stabilize and hold. If the fuel pressure does not reach a steady value, go to Fuel System Diagnosis. Component Tests and General Diagnostics
6. If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) of the average pressure drop value, the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting the second pressure reading from the first pressure reading.