Test NF-11A - Performing No Fault Mechanical Test
At this point in diagnostic test procedure, all engine control systems have been determined to be operating as designed and not causing a driveability problem. Following additional items should be checked as possible causes:
NOTE:
If coming to this test from O2 sensor test and rich or lean condition is not corrected after checking the following items, replace engine controller. Perform VERIFICATION TEST VER-3
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- Check if any TECHNICAL SERVICE BULLETINS (TSBs) apply to vehicle.
- Check engine vacuum. It must be at least 13 in. Hg in Neutral.
- Check valve timing.
- Check engine compression.
- Check for exhaust system restriction.
- Ensure PCV system is functioning properly.
- Check camshaft and crankshaft sprockets.
- Check torque converter stall speed.
- Check power brake booster for internal vacuum leak.
- Check for fuel contamination.
- Ensure injector control wire is connected to correct fuel injector and injector is not plugged or restricted.