Fuel Injected Engines

NOTE:
^ If the self diagnosis indicator blinks twelve times between pauses, check the # 16 and # 24 vacuum hoses for loose connections, disconnection of coupler connector, and open or short circuit, before making the following inspection.
^ Also perform the following inspection when the engine misses or runs rough at low speed, or when it tends to stall at idle, even if the self- diagnosis indicator does not blink.

1. Start the engine and warm it up until the cooling fan comes on.






2. Open the control box lid and disconnect # 16 vacuum hose from the top of the Exhaust Gas Recirculation (EGR) valve, then connect a hand vacuum pump to the hose.






3. Pinch the lower hose of the EGR control solenoid valve in the control box, and measure vacuum at idle.
^ If vacuum stabilizes between 150 and 250 mmHg (6 and 10 in.Hg) the Constant Vacuum Control (CVC) valve is OK.
^ If the amount of vacuum measured is outside 150-250 mmHg (6-10 in.Hg), check the hose between the intake manifold and vacuum gauge for clogging, kinking or leakage. If the hose is OK. replace the CVC valve and recheck.
4. Release the lower hose pinched in Step 3; again measure the amount of vacuum on the vacuum gauge.
^ If vacuum is below 30 mmHg (1.2 in.Hg), the EGR control solenoid valve is OK.
^ If the amount of vacuum exceeds 30 mmHg (1.2 in.Hg), check the air flow hose to the EGR control solenoid valve for blockage. If the hose is not collapsed or blocked, replace the EGR control solenoid valve and recheck.






5. Disconnect the # 21 vacuum hose from between the throttle body and manifold absolute pressure sensor. Plug the vacuum tap at the throttle body, connect a hand vacuum pump to the # 21 vacuum hose, and apply a vacuum of 300 mmHg (12 in.Hg).
6. Raise engine speed to 2,000-2,500 rpm. Feel operation of the EGR control solenoid valve with your fingers.
^ If the EGR control solenoid valve is operating, the system is OK.
^ If the EGR control solenoid valve is not operating, check the harnesses between the EGR control solenoid valve and Electronic Control Unit (ECU) (Red wire and Black/Yellow wire) for open or short circuits. If the harness is OK. then check the EGR control solenoid valve.
^ If the EGR control solenoid valve is normal check the EGR valve and lift sensor.