Test Procedure
- An engine cool down period of 10 minutes is necessary in order to avoid irregular readings due to hot soak fuel boiling. Connect fuel pressure gauge carefully to avoid any fuel spillage. The fuel pump should run about 2 seconds after ignition is turned to ON position.
- Insert a clear tube attached to vent valve of fuel pressure gauge into a suitable container. Bleed air from fuel pressure gauge and hose until all of air is bled from fuel pressure gauge. The ignition switch must be in OFF position at least 10 seconds in order to complete powertrain control module (PCM)/engine control module (ECM) shutdown cycle.
- Turn ignition ON in order to get fuel pressure to its maximum level. Allow fuel pressure to stabilize and then record this initial pressure reading. Wait until there is no movement of needle on fuel pressure gauge.
- Follow manufacturer's instructions for use of adapter harness. Energize fuel injector tester once and note fuel pressure drop at its lowest point. Record this second reading. Subtract it from first reading to determine amount of fuel pressure drop. Disconnect fuel injector tester from fuel injector.
- After turning ignition ON, in order to obtain maximum pressure once again, make a connection at next fuel injector. Energize fuel injector tester and record fuel pressure reading. Repeat this procedure for all injectors. Retest any of fuel injectors that pressure drop exceeds 10 kPa (1.5 psi) specification.
- Replace any of fuel injectors that fail retest. If pressure drop of all of fuel injectors is within 10 kPa (1.5 psi), then fuel injectors are flowing normally and no replacement should be necessary. Reconnect fuel injector harness and review symptom diagnostic tables.