Mitsubishi 3000GT 1991, Service Manual

Page: 356 / 1146

EMISSION CONTROL Exhaust Gas Recirculation (EGR) System
Engine speed
EGR SYSTEM INSPECTION <California
Turbo, Turbo>
Disconnect the vacuum hose (green stripe) from the EGR
valve, and connect a hand vacuum pump through the
three-way terminal.
(2) Regarding cold condition [coolant temperature: (68°F)
or less] and warm condition [coolant temperature: 70°C
(158°F) or more] of the engine, check the following two
points:
<Cold condition of engine>
<Warm condition of engine>
Engine operation
I
Normal state
Race the engine by
rapidly press in the
accelerator pedal.
The negative pressure rises
to
(3.9 or
more.
(3) Disconnect the three-way terminal, and connect the hand
vacuum pump to the EGR valve.
(4) When a negative pressure of 230 (9.1 is
applied during idling, check that the engine stops or idles
unstably.
EGR VALVE CONTROL VACUUM CHECK
<California Non Turbo, Turbo>
Check Condition
Engine coolant temperature: 80 95°C (176 205°F)
Disconnect the vacuum hose from the throttle body EGR
vacuum nipple and connect a hand vacuum pump to the
nipple.
(2) Start the engine and check to see that, after raising the
engine speed racing the engine, vacuum raises pro-
portionately with the rise in engine speed.
NOTE
If there is a problem with the change in vacuum, it is
possible that the throttle body port may be clogged and
require cleaning.