Egr System Cto Valve; Egr System Cto Valve Functional Test - Jeep 1987 Wrangler Workshop Manual

ENGINES
EXHAUST GAS RECIRCULATION SYSTEM
EGR VALVE REMOVAL
Remove the air cleaner assembly.
Identify, tag and disconnect the vacuum hoses.
Remove the E G R valve retaining nuts from the
manifold.
Remove the E G R valve, gaskets and restrictor
plate or spacer, if equipped.
Discard the gasket and clean the mating
surface.
EGR VALVE INSTALLATION
Install the E G R valve and a replacement gasket.
If the restrictor plate is used, place it between the
two replacement gaskets.
Install the retaining nuts and tighten.
Connect all the vacuum hoses.
Replace the air cleaner assembly.
EGR SYSTEM CTO VALVE
The E G R system C T O valve is located in the
coolant passage at the left front side of the
intake manifold.
T h e dual-function valve is also used for
distributor vacuum advance control.
The outer port (1) connects by a hose to ported
vacuum at the carburetor.
The inner port (2) connects by a hose to the E G R
thermal vacuum switch (TVS).
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When the coolant temperature is below the
calibrated rating of the C T O valve, there is no
vacuum applied to the E G R valve.
For six-cylinder engines, the C T O valve starts to
open at 4 6 ° C ( 1 1 5 ° F ) and at 5 7 ° C ( 1 3 5 ° F ) for
four-cylinder engines.
NOTE: The temperature ratings are nominal
values and the actual valve opening temper-
ature will vary slightly from unit to unit.
EGR SYSTEM CTO VALVE FUNCTIONAL TEST
NOTE: The engine coolant temperature must be
5 . 6 ° C ( 1 0 ° F ) below the calibrated opening
temperature of the valve.
Inspect the vacuum hoses for air leaks and
correct the routings/connections.
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