ENGINE
–
EMISSION CONTROL SYSTEMS
EGR SYSTEM INSPECTION
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
Disconnect the vacuum hose from the EGR valve and,
using a three way union,connect a vacuum gauge to it.
3. CHECK SEATING OF EGR VALVE
Start the engine and check that the engine starts and
runs at idle.
4. CHECK TVV WITH COLD ENGINE
(a) The coolant temperature should be below 30SC(86SF).
(b) Check that the vacuum gauge indicates zero at 3.500
rpm.
5. CHECK TVV AND EGR VACUUM MODULATOR
WITH HOT ENGINE
(a) Warm up the engine.
(b) Check that the vacuum gauge indicates low vacuum
at 3,500 rpm.
(c) Disconnect the vacuum hose from R port of the EGR
vacuum modulator and connect R port directly to the
intake manifold with another hose.
(d) Check that the vacuum gauge indicates high vacuum
at 3,000 rpm.
HINT: As a large amount of EGR gas enters, the
engine will misfire slightly at this time.
(e) Disconnect the vacuum gauge and reconnect the
vacuum hoses to the proper locations.
EG1–89