NTC-16A Checking the Engine Mechanical Systems

Vacuum Gauge Readings:

NOTE: At this point in the diagnostic test procedure, you have determined that all of the engine electrical systems are operating properly and are not the cause of the problem.

Check the following to determine the mechanical problem:
Engine Vacuum - should be at least 13 in Hg in neutral.

Engine Valve Timing - should be at manufacturer`s specifications.

Engine Compression - should match manufacturer's specifications.

Engine Exhaust System - must be free of any restrictions.

Engine PCV System - air must flow freely.

Engine Cam and Crankshaft Sprockets - must be properly positioned, and not have excessive wear.

Torque Converter Stall - speed must be within manufacturer`s specifications.

Power Brake Booster - should not have any internal vacuum leaks.

Fuel Contamination - check for high alcohol and/or water content.

Fuel Injector - check connection, and operation.

NOTE: If you came to this test from the oxygen sensor test, and the "RICH" or "LEAN" condition is not caused by one of the first items above, replace the Powertrain Control Module and perform verification TEST VER-2 (road test verification). Verification Test VER-2A - Road Test Verification