NF-13A Engine Mechanical Test

Vacuum Gauge Readings:

At this point in the driveability diagnosis, you have determined that all of the engine control systems are operating properly and are not the cause of the problem. The following items should be checked as possible mechanical causes of the problem:

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

VALVE TIMING: Engine valve timing should be at manufacturer`s specifications.

COMPRESSION: Engine compression should match manufacturer's specifications.

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

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

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.