Fuel Injected Engines

NOTE:
^ If the self diagnosis indicator blinks twelve times, check the # 16 and # 24 vacuum hoses for loose connection, disconnection of connector, and open or short circuit, before going into the steps described below.
^ 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 self-diagnosis system does not indicate a problem.

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 Exhaust Gas Recirculation (EGR) valve, and connect a 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 at 150-250 mmHg (6-10 in.Hg) within one second, the Constant Vacuum Control (CVC) valve and EGR hose routing is OK.
^ If vacuum is not 150-250 mmHg (6-10 in.Hg) within one second, check the hose between the intake manifold and the CVC valve for clogging, or leakage. If the hose is OK, replace the CVC valve.
4. Unclamp 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 and hoses are OK.
^ If the amount of vacuum exceeds 30 mmHg (1.2 in.Hg), check the air flow hose to the EGR control solenoid valve, and the # 17 vacuum hose for blockage. If the hoses are not collapsed or blocked, replace the EGR control solenoid valve and recheck.






5. Stop the engine. Reconnect the # 16 vacuum hose, then disconnect the # 21 vacuum hose from the throttle body. Plug the vacuum tap at the throttle body. connect a 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 EGR control solenoid valve. If the solenoid valve is OK, check Black/Yellow wire between the solenoid valve and Regulator fuse (10A), and Yellow wire between the solenoid valve and Electronic Control Unit (ECU). If wires are OK, see ECU troubleshooting. If the EGR control solenoid valve is normal, check the EGR valve and lift sensor.