Test NTC-4: Checking Engine Mechanical Systems
- At this point in diagnostic test procedure, all engine electrical 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 engine vacuum. Engine vacuum must be at least 13 in. Hg with transaxle in Neutral.
- Check engine valve timing.
- Check engine compression.
- Check camshaft lobes for abnormal wear.
- Check crankshaft notches (2.4L) or crankshaft sensor slots (2.5L) for debris or deterioration. On 2.4L, crankshaft contains 2 sets of notches ground into the No. 2 counterweight on the crankshaft. On 2.5L, there are 3 sets of sensor slots areas on flywheel which contain 4 slots in each set.
- Check exhaust system for restrictions.
- 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 fuel for contamination.
- Ensure proper injector driver wiring is installed on correct injector. Ensure injector is not plugged or restricted.
- Check for related Technical Service Bulletins (TSBs) that may apply to the problem.
- If coming to this test from an oxygen sensor test, and rich or lean condition is not corrected after checking items listed above, replace Powertrain Control Module (PCM). PCM is located at driver's side front corner of engine compartment, just below air cleaner assembly. Perform TEST VER-2A .