Range Rover P38
17
EMISSION CONTROL
NEW RANGE ROVER
26
DESCRIPTION AND OPERATION
SECONDARY AIR INJECTION SYSTEM COMPONENTS
Secondary air injection (SAI) pump
1. SAI pump cover
2. Foam filter
3. SAI pump
4. Pressurised air to exhaust manifolds
The SAI pump is attached to a bracket at the RH side
of the engine compartment. The pump is electrically
powered from a 12V battery supply via a dedicated
relay and supplies approximately 35 kg/hr of air when
the vehicle is at idle in Neutral / Park on a start from
20
°
C (68
°
F).
Air is drawn into the pump through vents in its front
cover and is then passed through a foam filter to
remove particulates before air injection. The air is
delivered to the exhaust manifold on each side of the
engine through a combination of plastic and metal
pipes.
The air delivery pipe is a flexible plastic type, and is
connected to the air pump outlet via a plastic quick-fit
connector. The other end of the flexible plastic pipe
connects to the fixed metal pipework via a short
rubber hose. The metal delivery pipe has a fabricated
T-piece included where the air is split for delivery to
each exhaust manifold via the vacuum operated SAI
control valves.
The pipes from the T-piece to each of the SAI control
valves are approximately the same length, so that the
pressure and mass of the air delivered to each bank
will be equal. The ends of the pipes are connected to
the inlet port of each SAI control valve through short
rubber hose connections.