Jeep 1996 Grand Cherokee Service Manual - page 1097
A special fixed orifice tool (number 6714) (Fig. 58)
must be used for the following test.
(1) Start the engine and bring to operating tem-
perature. Be sure all accessories are off before per-
forming this test.
(2) Shut off the engine and remove the air duct at
throttle body.
(3) Disconnect the vacuum line at the PCV valve
(Fig. 59).
(4) Install the 0.185 inch orifice tool (number 6714)
into the disconnected vacuum line in place of the
PCV valve (Fig. 59).
(5) Disconnect the idle purge vacuum line from fit-
ting at throttle body. This vacuum line is located on
the front of throttle body next to the MAP sensor
(Fig. 60). Cap the fitting at throttle body after vac-
uum line has been removed.
(6) Connect the DRB scan tool to the 16–way data
link connector. This connector is located under the
instrument panel to the left of the steering column.
Refer to the appropriate Powertrain Diagnostic Pro-
cedures service manual for DRB operation.
(7) Start the engine.
(8) Using the DRB scan tool, scroll through the
menus as follows: select—System, select—Engine,
select—Fuel and Ignition, select—Actuator Tests,
select—Engine rpm and select—Minimum Air Flow.
(9) The DRB scan tool will count down to stabilize
the idle rpm and display the minimum air flow idle
rpm. The idle rpm should be between 500 and 900
rpm. If the idle speed is outside of these specifica-
tions, replace the throttle body. Refer to Throttle
Body in the Component Removal/Installation section
of this group.
(10) Disconnect the DRB scan tool from the vehi-
cle.
(11) Remove cap from idle purge fitting at throttle
body and install vacuum line.
(12) Remove orifice tool and connect vacuum line
to PCV valve.
(13) Install air duct to throttle body.
REMOVAL AND INSTALLATION
AUTOMATIC SHUTDOWN (ASD) RELAY
The ASD relay is located in the Power Distribution
Center (PDC) (Fig. 61). Refer to label on PDC cover
for relay location. Check terminal connections at
PDC and relay for damage/corrosion before installa-
tion. Repair as necessary.
FUEL PUMP RELAY
The fuel pump relay is located in the Power Distri-
bution Center (PDC) (Fig. 61). Refer to label on PDC
cover for relay location. Check terminal connections
at relay and PDC for damage/corrosion before instal-
lation. Repair as necessary.
Fig. 58 Fixed Orifice Tool
Fig. 59 Install Orifice Tool
Fig. 60 Idle Purge Line
14 - 52
FUEL SYSTEM
ZJ
DIAGNOSIS AND TESTING (Continued)