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.

Perform the following mechanical checks to determine the cause of the problem:

Engine Vacuum: Engine vacuum should be at least 13 in Hg in neutral.

Engine Valve Timing: Engine valve timing should be at manufacturer`s specifications.

Engine Compression: Engine compression should match manufacturer's specifications.

Engine Exhaust System: The engine exhaust system must be free of any restrictions.

Engine PCV System: Air in the PCV system must flow freely.

Engine Drive Sprockets: Cam and crankshaft sprockets must be properly positioned, and not have excessive wear.

Torque Converter Stall: Torque converter stall speed must be within manufacturer`s specifications.

Power Brake Booster: The power brake booster should not have any internal vacuum leaks.

Fuel Contamination: Check the fuel system for high alcohol and/or water content.

Fuel Injectors: Check the injectors for proper connection, and injector operation.

NOTE: Always check for service bulletins which may relate to the problem.

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