Test NTC-13A: Checking Engine Mechanical Systems

NOTE: Perform DTC P0171-B: 1/1 FUEL SYSTEM LEAN , DTC P0172-B: 1/1 FUEL SYSTEM RICH , DTC P0174-B: 2/1 FUEL SYSTEM LEAN , DTC P0175-B: 2/1 FUEL SYSTEM RICH or TEST NTC-10A: CHECKING OXYGEN SENSOR SWITCHING 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: ROAD TEST VERIFICATION .

At this point in diagnostic test procedure, all engine electrical 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 (TSB) relating to driveability problem.
Check engine vacuum. Engine vacuum must be at least 13 in. Hg in 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.