Fuel Injector Balance Test - With Scan Tool

FUEL INJECTOR BALANCE TEST WITH SCAN TOOL UNIT

The Saturn Scan tool (PDT) unit can be used to diagnose individual fuel injector and cylinder performance with the engine at an idle RPM. The Scan tool should be set to a fast update speed and programmed to monitor long term fuel trim/short term fuel trim fuel variance from cylinder to cylinder by disconnecting one fuel injector at a time and reconnecting it. The engine must be at operating temperature and the electronic control system must remain in closed loop when performing this test.

After each fuel injector connector is disconnected, allow the integrator to stabilize and record the highest reading obtained. Next, plug the fuel injector connector back in and record lowest short term fuel trim reading. Under normal conditions with the engine in closed loop and at idle, short term fuel trim readings should not vary more than 5 short term fuel trim counts from cylinder to cylinder.

NOTE: The entire test must be completed at least twice. The engine must be kept in closed loop and at operating temperature.