Toyota 4-Runner 1985 Repair Manual page 124

EC-24
EMISSION CONTROL SYSTEMS (CARB.)
Fuel Evaporative Emission Control
(EV AP) System
To Canister
EC0308
Below 7 mph
Speedometer Vacuum Gauge
EC0144 EC0128
Above 16 mph
Speedometer
Vacuum Gauge
EC0145 EC0130
EC0307
EC0309
INSPECTION OF SPEED SENSOR TO VSV
1. CONNECT VACUUM GAUGE
(a) Using a 3-way connector, connect the vacuum gauge
to the hose between the VSV and canister.
(b) Set the gauge at the driver's seat.
A03042
2. PERFORM ROAD TEST, OBSERVING SPEEDOMETER AND
VACUUM GAUGE
(a) Warm up the engine.
(b) Check that the vacuum gauge indicates zero at low
speed driving (below 7 mph or 11 km/h).
(c) Check that the vacuum gauge indicates intake
manifold vacuum at middle and high speed driving
(above 16 mph or 25 km/h).
If a problem is found, inspect speed sensor and VSV.
3. REMOVE VACUUM GAUGE AND RECONNECT HOSE
INSPECTION OF VSV
1. CHECK VACUUM CIRCUIT CONTINUITY IN VSV BY
BLOWING AIR INTO PIPE
(a) Connect the VSV terminals to the battery terminal as
shown.
(b) Blow into a pipe, and check that the VSV is open.
(c) Disconnect the battery positive
(+)
terminal.
(d) Blow into a pipe and check that the VSV is closed.