Toyota 4-Runner 1985 Repair Manual page 151

EMISSION CONTROL SYSTEM (CARB.) - High Altitude Compensation (HAC) System EC-51
EC0380
EC0381
Lower Port
EC0340
(d) Reconnect the hose to the sub-diaphragm.
(e) Check that the ignition timing advances.
Ignition timing: About 12° BTDC
@
Max. 950 rpm
2. CHECK THE CHECK VALVE
(a) Disconnect the vacuum hose from lowest port of the
HAC valve, and plug the hose end.
(b) Disconnect the vacuum hose between the check valve
Check Valve
and vacuum pipe at the pipe side, and plug the pipe
EC0382
EC0383
end.
(c) Check that the ignition timing remains stationary for
more than one minute.
(d) Stop the engine and reconnect the hoses to the vacu-
um pipe and HAC valve.
3. CHECK CARBURETOR
(a) Disconnect three hoses from the pipes on top of the
HAC valve.
(b) Blow air into each hose and check that air flows into
the carburetor.
(c) Reconnect the hoses to the proper locations.
IF NO PROBLEM IS FOUND WITH THIS INSPECTION, THE
SYSTEM IS OKAY; OTHERWISE INSPECT EACH PART