Oxygen (O2) Sensor Replacement; Electronic Controlunit (Ecu) Replacement (Located Under Passenger Seat); Control Relay Replacement; Air Intake System Leak Test - Winnebago 1987-1989 LeSharo Service Manual

ENGINE FUEL SYSTEM
COMPONENT REPLACEMENT
OXYGEN
(02)
SENSORREPLACEMENT
Disconnect the wire harness connector.
Remove the oxygen
(02)
sensor from the exhaust
pipe with a flare head crow foot wrench (22 mm x
3/8 in drive).
When installing the replacement sensor, apply
antiseize compound to the threads.
CAUTION
Apply antiseize compound to the threads only
and not to any other part of the sensor.
Hand start the replacement sensor into the
adaptor.
Tighten the sensor with 3.8 - 4.6 daNm (28-34
Ib.lft.) torque with a flare head crow foot wrench
(22 mm x 3/8 in drive).
ELECTRONIC CONTROLUNIT (ECU) REPLACEMENT
(Located under passenger seat)
Remove cover and then remove the retaining
screw. Remove the ECU from the bracket.
Disconnect the wire harness connector.
Connect the wire harness connector to the
replacement ECU and install it in the bracket.
Tighten the screw.
CONTROL RELAY REPLACEMENT
Precautions
Never connect or disconnect a wire harness with
the ignition switch on.
With the engine stopped and the ignition switch
ON, the fuel pump should not be operate. Its
input circuit passes through the control relay,
which remains de-energized until the starter
motor is engaged.
C3-6
Procedure
Remove the relay from the right side of the
firewall by first removing the bolt at the top of
the relay. Remove the wire harness connector
from the relay.
Connect the wire harness connector to the new
replacement relay. Refasten the bolt on the top of
the replacement relay. Refasten the bolt on the
top of the relay to the firewall.
AIR INTAKE SYSTEM LEAK TEST
Special Precautions
Before performing any test, ensure:
- that the problem is not caused by something
other than the fuel system (e.g., spark plugs,
distributor, ignition timing, etc.)
- that no air is entering the intake or the exhaust
system ahead of the catalytic converter.
- that fuel is actually reaching the injectors
(check the pressure in the fuel circuit)
Procedure:
- Disconnect the hose from the valve cover.
Usea brush and apply a soapy water solution to
all components that are likely to develop leaks
(seals, air hoses, etc.)
Plug the exhaust pipe with a cloth or similar
object.
Force compressed air (1 bar/1S psi max.) into
the air intake hose at T. (See illustration on
following page.)
Open the throttle plate.
The appearance of bubbles or foam indicates
location of an air leak in the system.
CAUTION
If the air temperature is likely to exceed
80°C/176°F(as in a body shop paint curing oven,
for example), remove the electronic control unit
(ECU) from the vehicle.
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