Engine Controls - System/component Tests - 3.2L: Diagnosis

Engine Controls - System/component Tests - 3.2L: Diagnosis Honda Passport I

Fuel Injector Balance Test

Connect fuel pressure gauge to fuel rail. Disconnect vacuum hose at pressure regulator. Turn ignition on. Note fuel pressure. Fuel pressure should be 35-38 psi (2.5-2.7 kg/cm 2 ). Start engine. Reconnect vacuum hose. Fuel pressure should decrease slightly. NOTE: Fuel pressure must be correct before proceeding with fuel injector balance test.
With ignition off, unplug harness connectors at all injectors. Install Injector Tester (J-34730-3 ) on one injector. Turn ignition on. Bleed off air in fuel pressure gauge. Fuel pump should operate for about 2 seconds.
Turn ignition off for 10 seconds. Turn ignition on with engine off. Turn injector on by pressing button on injector tester. Note pressure drop as soon as gauge needle stops. Pressure may increase for a few seconds after initial pressure drop.
Injector pressure drop should be similar for all injectors. Replace any injector with more than a 1.45 psi (10 kg/cm 2 ) difference from other injectors.

DIAGNOSTIC CHARTS

Note. In the following Diagnostic Trouble Code (DTC) testing, illustrations and schematics are courtesy of Isuzu Motor Co., Inc.

Diagnostic Aids

A poor connection at oxygen sensor could cause a false code to set or heater malfunction. A shorted heater could cause a Code 13 to set.

If EGR system works properly, check for restricted EGR passages or defective MAP sensor. These items could cause high block learn values in open throttle, but not in closed throttle.

CHART C-10 - A/C CLUTCH CONTROL DIAGNOSIS

When A/C is turned on, ECM supplies ground for A/C control relay. Battery voltage is supplied to A/C clutch solenoid through thermoswitch relay. This relay is part of A/C on/off switch circuit. If A/C system exhibits high pressure or overheating condition, system will be turned off by A/C high pressure safety switch or by A/C thermoswitch circuit.