Preliminary Checks

Most driveability problems in the engine control system result from faulty wiring or leaking hose connections. To avoid unnecessary component testing, a visual check should be performed before beginning trouble shooting procedures to help spot these common faults. A preliminary visual check should include:

• Air ducts to air cleaner and from air cleaner to throttle body.
• Electrical connections at all components. Clean, tight and unbroken.

Check vacuum lines for secure, leak-free connections in these areas:

• Canister purge hose (this hose has a tee connector in it.)
• EGR vacuum line on EGR valve and EGR solenoid. Check hose between backpressure valve and exhaust supply tube on EGR.
• Evaporative control system.
• Fuel pressure regulator vacuum hose.
• MAP sensor.
• PCV valve hose and correct PCV valve.
• Power brake, speed control, heater and A/C system vacuum hoses.
• Throttle body.

Ensure the following electrical connectors are securely attached:

• 14-pin and 60-pin connectors at Single Module Engine Controller (SMEC).
• A/C clutch relay connector.
• AIS motor connector.
• ASD relay connector.
• Canister purge solenoid connector.
• Charge temperature sensor connector.
• Check engine light.
• Coolant temperature sensor connector.
• Distance (speed) sensor connector.
• Distributor connector.
• EGR diagnostic solenoid connector (California only).
• Fuel injector connector.
• Heated O2 sensor connector.
• MAP sensor connector.
• Radiator fan relay connector.
• TPS connector.