System Testing: Notes
- With intake air temperature less than 158°F (70°C), remove air cleaner cover and filter element. Disconnect hose from main air jet solenoid valve and install vacuum pump. Start engine and apply 4 in. Hg to solenoid at idle. If vacuum does not hold, proceed to step 4).
- If vacuum holds, release vacuum and warm engine to operating temperature (cooling fan comes on). Apply vacuum to solenoid. If vacuum does not hold, system is functioning properly.
- If vacuum does hold with engine at operating temperature, turn ignition off. Disconnect Green connector near air cleaner. Start engine. Measure voltage between ground and Green terminal wire. If voltage is not present, replace solenoid. If voltage is present and PGM-CARB warning light on dash is not illuminated, substitute a known good ECU and retest. If symptom is rectified, replace original ECU.
- If vacuum did not hold in step 2) and intake air temperature was less than 158°F (70°C), warm engine to operating temperature (cooling fan comes on). Turn ignition off. Disconnect Green wire connector near air cleaner. Start engine. Measure voltage between ground and Green wire terminal. If voltage is present, replace solenoid. If voltage is not present and PGM-CARB warning light on dash is not illuminated, substitute a known good ECU and retest. If symptom is rectified, replace original ECU.