Table of Contents
Advertisement
1977 Volvo 242 244 245
The air is drawn into the air pump via an air filter. The compressed air is fed out of the pump through the
diverter valve. This valve has two functions. It regulates the air pump pressure. It also shuts off the air
WWW.MANUALS.WS
delivery when using the engine to brake. If the system was allowed to operate under this condition, fresh
air mixed with the overly rich vapor would cause a backfire.
The backfire valve admits air into the exhaust manifold but prevents return of exhaust gas to the air
pump incase of a backfire or air pump malfunction, such as drive belt damage.
Air Injection Reactor check
This system should be checked every 15,000 miles. Hoses and connections should be checked for leaks
and condition. Check the diverter valve and backfire valve operation. Check the operation of the air
pump and that there is no excessive noise.
The exhaust emissions will be incorrect if the AIR System does not operate properly.
Catalytic Converter
This is a supplementary device in the exhaust system, designed to clean the remaining dirty exhaust
gases.
This device is mainly a container with a ceramic material insert, designed to let the exhaust gases pass
through channels in the insert. The channel walls are covered by a thin layer of platina-palladium. These
metals act as catalysts, permitting a chemical process without actually taking part in it.
The CO content will increase if the Catalytic Converter is damaged.
pg. 55 Emission control systems
NOTE:
Vehicles with Catalytic Converter must use unleaded fuel only. Otherwise the Catalytic Converter will
be destroyed.
Torque catalytic converter mounting bolts (certain models)
WWW.MANUALS.WS
The catalytic converter mounting bolts should be torqued every 15,000 miles.
VI Engine Evaporative Emissions
file:///K|/ownersdocs/1977/1977_242_244_245/77242244245_03a.htm (15 of 16)12/22/2006 10:07:33 PM
Advertisement
Table of Contents
