Jeep cherokee 1989, Owner'S Manual

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6-12 Chapter 6 Emissions and engine control systems
and, with the engine operating at about 1 5 0 0 rpm, squeeze the
hose. You should be able t o feel the air pulsing through the hose.
Have an assistant increase the engine speed. There should be
a proportional increase in air flow. If there is, the pump is working
properly. If there isn't, the pump is malfunctioning. Replace it
(see the component replacement procedure below).
7
To test a check valve:
a) Remove it (see the component replacement procedure below).
Clean it off thoroughly.
Try t o blow through it from each end. Air should only pass
through it in the direction of normal flow (towards the exhaust
manifold). If the valve is open both ways or closed both ways,
replace it.
Pulse air system
8
Checking the pulse air system is beyond the scope of the home
mechanic and can be hazardous under certain circumstances. Take the
vehicle t o a dealer service department or a certified emission control
repair shop for testing.
Component replacement
Refer to illustrations 5. 5.14, 5.19, 5.30 and 5.32
9 Always detach the cable from the negative terminal of the battery
before replacing any of the following components.
5.1 1 To remove the air pump pulley, loosen the three
bolts, remove the drivebelt, then remove the bolts
Drivebelt (air pump system only)
1 0 Drivebelt replacement procedures are in Chapter 1.
Air pump pulley and filter
11 Compress the drivebelt t o prevent the pulley from turning and
loosen the pulley attaching bolts (see illustration).
1 2 Remove the drivebelt (see Chapter
1 3 Remove the pulley attaching bolts and detach the pulley.
1 4 To remove the air pump filter, grasp it firmly with needle
pliers (see illustration) and pull it from the pump. Caution: The filter
will probably be damaged when you pull i t off, so make sure no
fragments fall into the air intake hose. Don't insert a screwdriver bet-
ween the filter and the pump housing
-
you might damage the edge
of the housing.
1 5 To install the new filter, place it in position, place the pulley in posi-
tion and tighten the pulley bolts evenly. As the pulley bolts are tightened,
the pulley will press the filter into the pump. Caution: Do not attempt
to install a filter by pressing or hammering i t into place.
1 6 The remainder of installation is the reverse of removal. Note:
is normal for the new filter to have an interference fit with the pump
housing. It may squeal in operation until it's worn in.
Hoses and tubes
1 7 Before replacing any hose or tube, note how it is routed. Make
a sketch or label the components t o which it's attached.
18 Be sure t o replace old hoses or tubes with new ones of the same
size and material. Tighten all connections securely.
Check (air pump system only)
1 9 Remove the hose clamp and detach the air hose from the check
(see illustration).
2 0 Unscrew the check valve from the air injection manifold. Use a
backup wrench so you don't bend or twist the manifold.
21 Installation is the reverse of removal. If you are replacing the valve,
compare the new valve with the old one to be sure you have the correct
replacement.
Diverter valve (air pump system only)
2 2 Detach the vacuum signal line and the air hoses from the diverter
valve (see illustration
5.6).
2 3 Remove the mounting bolts (the bolts may have tabbed lock
washers which you will have to bend back).
2 4 lnstallation is the reverse of removal.
Air injection (air pump system only)
2 5 Detach the air from the air injection manifold check
(see the check valve replacement procedure above).
26 Using a flare nut wrench (if available), unscrew the three fittings
that attach each air injection manifold to its associated exhaust manifold
(see illustration
5 . 6 ) .
5.14 To remove the air pump filter, grasp it firmly w i t h
needle-nose pliers and pull it from the pump
-
be sure no
filter fragments fall into the air intake hose!
5.19 To remove a check valve, loosen the hose clamp
and detach the air hose from the valve, then unscrew the
valve from the air injection manifold be sure t o use a
backup wrench so you don't damage the manifold
The Motor Manual Guy