Test NTC-18A - Checking Engine Mechanical Systems

NOTE: Perform TEST TC-118A TEST TC-119A TEST NTC-7A TEST NTC-7B TEST NTC-14A or TEST NTC-17B before proceeding.

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). 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 for Technical Service Bulletins (TSBs) relating to driveability problem.
Check engine vacuum. Engine vacuum must be at least 13 in. Hg with transmission in Neutral.
Check engine valve timing.
Check engine compression.
Check camshaft lobes for abnormal wear.
Check crankshaft sensor pick-up. Check crankshaft slots for debris or deterioration.
Check exhaust system for restrictions.
Ensure PCV system is functioning properly.
Check camshaft and crankshaft sprockets for proper position.
Check torque converter stall speed.
Check power brake booster for internal vacuum leak.
Check fuel for contamination.
Ensure proper injector driver wiring is installed on correct injector. Ensure injector is not plugged or restricted.