LAND ROVER DISCOVERY 1999 Workshop Manual

EMISSION CONTROL - V8
17-2-48 DESCRIPTION AND OPERATION
Test 2 – Secondary Air Injection (SAI) Control Valves
1SAI control valve
2Pressure connection
3Outlet4Inlet connection stopper
5Hand pressure pump
6Hand vacuum pump
Visually inspect the SAI control valve for external damage.
Leak Test
Remove the line from the inlet connection and connect the hand pressure pump (5) using the inlet connection stopper
(4). Using the hand pressure pump, pressurise the SAI control valve with 100 mBar (1.45 lbf/in
2) pressure. Maximum
permissable pressure drop at the hand pressure pump gauge 10 mbar/minute (0.145 lbf/in2/minute) with the outlet (3)
open.
Valve Opening Test
Connect the hand vacuum pump (6) to the control pressure connection (2). Depressurise the pressure connection
using the hand vacuum pump. When the vacuum reaches -300 mbar (-4.35 lbf/in
2), the SAI control valve (1) must
open and the pressure on the hand pressure pump (5) gauge should drop suddenly.
Tightness of Diaphragms
The available pressure difference (vacuum) at the control pressure connection (2) must not drop over a period of time
(Refer to Valve Opening Test).
NOTE: In the case of a leaking or incorrectly controlled SAI control valve, the inlet connection is usually heavily fouled
and a condensate smell is noticeable on the hose line to the SAI pump.
If, after switching off the SAI pump, pulsation noise is still noticeable at the SAI pump, the SAI control valve and
delivery hoses must be replaced before fitting a new SAI pump.
M17 0376
3
65
1
4
2

EMISSION CONTROL - V8
DESCRIPTION AND OPERATION 17-2-49
Test 3 – Vacuum Solenoid Valve
Function
The vacuum solenoid valve is energised for the duration of the secondary air injection. The valve is open when
energised, the intake manifold vacuum acts on the diaphragm of the SAI control valve and the control valve opens.
The solenoid valve is closed when de-energised.
Power Supply
Remove the harness connector from the vacuum solenoid valve and check the voltage between the connection
terminals. No voltage must be present at the connector after switching off the SAI pump.
Opening/Tightness
Disconnect the vacuum line at one of the SAI control valves and connect a hand vacuum pump to the line. With the
engine running at idle, a pressure difference of a minimum of 390 mbar (5.65 lbf/in
2) must measurable on the hand
vacuum pump gauge with the vacuum solenoid valve energised.
The vacuum solenoid valve must be sealed when de-energised. If the Opening/tightness test fails, replace the
vacuum solenoid valv.
Test 4 – Delivery Hoses to Secondary air Injection (SAI) Control Valves
Visually inspect the delivery hoses to the SAI control valves for damage or blockage. If damage, condensate or
deposits are found the delivery hoses must be replaced. Check the hoses for correct connection and leaks.
Test 5 – Connection to Air Manifold
Check the connection for leaks visually or by using a leak detection spray. Reseal the connection if necessary.
Test 6 – Vacuum Lines
Visually inspect the vacuum lines for damage. Check each line for leaks or blockages using the vacuum hand pump.
Check the lines for correct connection.

EMISSION CONTROL - V8
REPAIRS 17-2-51
REPAIRS
Canister - EVAP
$% 17.15.13
Remove
1.Raise vehicle on lift.
2.Remove 2 bolts securing canister bracket to
chassis.
3.Remove bolt securing canister to bracket and
remove bracket.
4.Release clip and disconnect atmosphere vent
pipe from canister.
5.Release and remove purge and tank vent pipes
from canister.
6.Remove EVAP canister.
CAUTION: Always fit plugs to open
connections to prevent contamination.Refit
1.Ensure all connections are clean.
2.Position new canister and connect purge and
tank vent pipes.
3.Connect atmospheric vent pipe to canister and
secure with clip.
4.Fit bracket to canister and secure with bolt.
5.Fit canister and bracket and secure with bolts.

EMISSION CONTROL - V8
17-2-52 REPAIRS
Canister - EVAP - Models with Fuel Leak
Detection Pump - up to 03MY
$% 17.15.13
Remove
1.Raise vehicle on lift.
2.Remove 3 Torx screws securing fuel leak
detection pump to mounting bracket.
3.Remove 3 bolts securing EVAP canister
mounting bracket to chassis longitudinal.4.Remove 2 bolts securing EVAP canister to
mounting bracket and collect clamp.
5.Remove mounting bracket.
6.Position cloth to absorb any fuel spillage.
7.Release purge and tank vent pipes from EVAP
canister.
8.Remove clip securing fuel leak detection pump
pipe to EVAP canister.
9.Release pipe from EVAP canister and remove
canister.
CAUTION: Plug the connections.
Refit
1.Remove plugs and ensure all connections are
clean.
2.Connect fuel leak detection pump pipe to EVAP
canister and secure with clip.
3.Connect purge and tank vent pipes to EVAP
canister.
4.Position mounting bracket to EVAP canister
and secure with bolts.
5.Position mounting bracket to chassis
longitudinal and tighten bolts.
6.Fit Torx screws securing fuel leak detection
pump to mounting bracket.
7.Lower vehicle.
M17 02192
M17 0220
M17 0221
4
4
4
9
7
7
5
8

EMISSION CONTROL - V8
REPAIRS 17-2-53
Canister - EVAP - Models with Fuel Leak
Detection Pump - from 03MY
$% 17.15.13
Remove
1.Raise the vehicle on lift.
2.Disconnect multiplug from the fuel leak
detection pump.
3.Disconnect the fuel leak detection filter pipe
from the fuel leak detection pump.
4.Release clips and disconnect 2 vent pipes from
the EVAP canister.
CAUTION: Always fit plugs to open
connections to prevent contamination.5.Remove and discard 4 bolts securing EVAP
canister mounting bracket to the chassis and
remove the EVAP canister assembly.
NOTE: Do not carry out further dismantling if
component is removed for access only.
6.Remove bolt securing EVAP canister retaining
clamp to the mounting bracket and collect the
clamp.
7.Remove nut and bolt securing EVAP canister to
the mounting bracket.

EMISSION CONTROL - V8
17-2-54 REPAIRS
8.Remove and discard clip securing fuel leak
detection pump fuel pipe to the EVAP canister
and disconnect the fuel pipe.
9.Remove the EVAP canister.
Refit
1.Position EVAP canister to the mounting
bracket.
2.Connect fuel leak detection pump fuel pipe to
the EVAP canister and secure with a new clip.
3.Fit nut and bolt securing EVAP canister to the
mounting bracket and tighten to 10 Nm (7 lbf.ft).
4.Position EVAP canister retaining clamp to the
mounting bracket, fit bolt and tighten to 10 Nm
(7 lbf.ft).
5.Position EVAP canister mounting bracket to the
chassis, fit new bolts and tighten to 25 Nm (18
lbf.ft).
6.Connect vent pipes to the EVAP canister.
7.Connect multiplug to the fuel leak detection
pump.
8.Connect the fuel leak detection filter pipe to the
fuel leak detection pump.
9.Lower the vehicle lift.
Valve - purge control
$% 17.15.39
Remove
1.Disconnect multiplug from purge control valve.
2.Release clips securing hoses to purge control
valve.
3.Disconnect hoses from purge control valve and
remove valve.
CAUTION: Always fit plugs to open
connections to prevent contamination.
Refit
1.Position purge control valve and connect
hoses.
2.Fit clips to secure hoses to purge control valve.
3.Connect multiplug to purge control valve.

EMISSION CONTROL - V8
REPAIRS 17-2-55
Solenoid - evap canister vent solenoid
(CVS) valve
$% 17.15.47
Remove
1.Disconnect multiplug from CVS unit.
2.Remove clip and disconnect hose from vent
valve.
CAUTION: Always fit plugs to open
connections to prevent contamination.
3.Remove CVS unit from bracket. Refit
1.Fit CVS unit to bracket.
2.Connect hose to vent valve and secure with
clip.
3.Connect multiplug to CVS unit.

EMISSION CONTROL - V8
17-2-56 REPAIRS
Sensor - heated oxygen (HO2S) - pre-
catalytic converter
$% 19.22.16
Remove
1.Raise vehicle on a ramp.
2.Release HO
2S multiplug from support bracket.
3.Release HO
2S harness from clip and
disconnect multiplug from HO
2S .
4.Using a 22 mm crow's-foot spanner, remove
HO
2S.
CAUTION: HO
2 sensors are easily damaged
by dropping, excessive heat or
contamination. Care must be taken not to
damage the sensor housing or tip.Refit
1.Clean sensor and exhaust pipe mating
surfaces.
2.If refitting existing sensor, apply anti-seize
compound to sensor threads.
WARNING: Some types of anti-seize
compound used in service are a health
hazard. Avoid skin contact.
NOTE: A new HO
2 sensor is supplied pre-
treated with anti-seize compound.
3.Fit a new sealing washer to HO
2S
4.Fit HO
2S and tighten to 45 Nm (33 lbf.ft).
5. Connect multiplug to HO
2S, and secure to
support bracket and harness clip.
6.Lower vehicle.

EMISSION CONTROL - V8
REPAIRS 17-2-57
Sensor - heated oxygen (HO2S) - post-
catalytic converter
$% 19.22.17
Remove
1.Raise vehicle on ramp.
2.Release HO
2S multiplug from support bracket.
3.Disconnect HO
2S multiplug from harness.
4.Using a 22 mm crowsfoot spanner, remove
HO
2S.
CAUTION: HO2 sensors are easily damaged
by dropping, excessive heat or
contamination. Care must be taken not to
damage the sensor housing or tip.Refit
1.Clean sensor and exhaust pipe mating
surfaces.
2.If refitting existing sensor, apply anti-seize
compound to sensor threads.
WARNING: Some types of anti-seize
compound used in service are a health
hazard. Avoid skin contact.
NOTE: A new HO2 sensor is supplied pre-
treated with anti-seize compound.
3.Fit a new sealing washer to HO
2S
4.Fit HO
2S and tighten to 45 Nm (33 lbf.ft).
5. Connect HO
2S multiplug to harness and fit
harness to bracket.
6.Secure harness to clip.
7.Lower vehicle.