Dr-18: No Fault Code Mechanical Test

At this point in the Test DR-procedure, you have determined that all engine control systems and sensors are operating properly. Therefore, they are not the cause of the driveability problem. The following areas should also be examined:

• Check for dirt or ice build-up around throttle valve area.
• Check ignition timing.
• Check engine vacuum.
• Check engine compression.
• Check valve timing.
• Check for plugged PCV system.
• Check for exhaust system restriction.
• Check for power brake booster vacuum leaks.
• Check torque converter condition.
• Check fuel injector wiring.
• Check secondary ignition circuit for abnormal scope pattern.
• Check for fuel contamination.
• Ensure fuel pressure is within specification. See FUEL PRESSURE SPECIFICATIONS  table.
• Check fast idle air valve. Ensure coolant circulates through valve.
• Check if any TECHNICAL SERVICE BULLETINS (TSBs) apply to this vehicle.