Mitsubishi 3000GT Service Manual page 523

ENGINE AND EMISSION CONTROL - Emission Control System
e h o s e - - -
Vacu-
um
Engine speed (rpm)
Engine operating
Applying vacuum
condition
3,000 rpm 375 mmHg
(14.8 in.Hg)
Engine operating
Applying vacuum
condition
3,000 rpm within Try applying
three minutes af- vacuum
ter starting engine
(4) Connect the vacuum hose (red stripes) removed in (1)
above to P nipple of the throttle body as before.
(5) Disconnect the purge air hose from the air intake hose,
and plug the air intake hose. Then, connect the hand
vacuum pump to the purge air hose.
(6) Apply vacuum in hot engine [coolant temperature: 70°C
(158°F) or higher], and check to see that vacuum leak
is caused when performing a sudden racing.
PURGE PORT VACUUM CHECK
Engine coolant temperature: 80-95°C (176-205°F)
(1) Disconnect the vacuum hose from the throttle body purge
hose nipple and connect a hand vacuum pump to the
nipple.
(2) Start the engine and check to see that, after raising the
engine speed by racing the engine.
Vacuum raises proportionately with the rise in engine
speed.
NOTE
If there is a problem with the change in vacuum, it is
possible that the throttle body purge port may be clogged
and require cleaning.
Result
Vacuum is maintained
Result
Vacuum leaks