C-4 Diagnostics

The C-4 system may be suspected when engine performance, fuel economy or exhaust emissions are improper. A built-in diagnostic system is likely to activate if a problem occurs in the system (however, there is the possibility of this not happening). If the C-4 system contains a problem, a "CHECK ENGINE" warning light will be activated on the instrument panel. If, however, the warning light is not activated, the following items should be checked before inspecting the C-4 system further:

• Ignition system (dist., timing, plugs, etc.)
• Air cleaner system
• Fuel evaporation system
• Early fuel evaporation system
• PCV system
• EGR valve
• Engine compression
• Intake manifold
• Vacuum hoses
• Carburetor mounting bolts