Test NTC-22A - Checking Engine Mechanical Systems: Notes

(GASOLINE ENGINES)

NOTE: This test applies to gasoline engines only. For testing on diesel engines, perform TEST NTC-22B.

NOTE: If coming to this test from an oxygen sensor test, and rich or lean condition is not corrected after checking items listed below, replace Powertrain Control Module (PCM) and perform TEST VER-2A.

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:

* Check distributor position. See CHECKING DISTRIBUTOR POSITION WITH SCAN TOOL.

* Ensure engine vacuum is at least 13 in. Hg in Neutral.

* Check valve timing.

* Check engine compression.

* Check for exhaust system restrictions.

* Check PCV system for proper function.

* Ensure engine drive sprocket is properly positioned.

* 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.

NOTE: Setting distributor position does not adjust ignition timing. Ignition timing is controlled by PCM.

WARNING: Avoid contact with moving engine parts.