Toyota Land Cruiser 1988 Repair Manual page 122

EMISSION CONTROL SYSTEMS- Exhaust Gas Recirculation (EGR) System
EC-13
COLD
2,500 rpm
Tachometer
HOT
2,500 rpm
Tachometer
Vacuum Gauge
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Filter
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EC2011
EC2037
No Vacuum
Vacuum Gauge
EC0137 EC0128
Low Vacuum
Vacuum Gauge
EC0137 EC01 29
EC3038
INSPECTION OF EGR SYSTEM
1. CHECK AND CLEAN FILTER IN EGR VACUUM
MODULATOR
(a) Check the filter for contamination or damage.
(b) Using compressed air, clean the filter .
2. PREPARATION
Using a 3-way connector, connect a vacuum gauge to
the hose between the EGR valve and vacuum pipe.
3. CHECK SEATING OF EGR VALVE
Start the engine and check that the engine starts and runs
at idle.
4. CHECK VSV WITH COLD ENGINE
(a) The coolant temperature should be below 53oC
(127°F).
(b) Check that the vacuum gauge indicates zero at
2,500 rpm.
5. CHECK VSV AND EGR VACUUM MODULATOR
WITH HOT ENGINE
(a) Warm up the engine.
(b) Check that the vacuum gauge indicates low vacuum
at 2,500 rpm.
(c) Check that the vacuum gauge indicates zero at idle.
(d) Disconnect the vacuum hose from port R ofthe EGR
vacuum modulator and connect port R directly to
the intake manifold with another hose.
(e) Check that the vacuum gauge indicates high vac-
uum at 2,500 rpm.
NOTE: As a large amount of EGR gas enters, the engine
will misfire slightly.
(f) Remove the vacuum gauge and reconnect the vac-
uum hoses to the proper locations.