Suzuki Samurai 1986 Service Manual page 168

EGR DIAGNOSIS
Condition
Engine idles abnormally rough
and/or stalls.
Engine runs rough on light
throttle acceleration and has
poor part load performance.
Engine stalls on decelerations.
Part throttle engine detonation.
NOTE:
Non-functioning EGR valve
could contribute to part
throttle detonation. Detonation
can be caused by several other
engine variables. Perform igni-
tion and carburetor related
diagnosis.
5-16
Possible Cause
EGR valve vacuum hoses mis-
routed.
Leaking EGR valve.
EGR valve gasket failed or loose
EG R attaching bolts.
Improper vacuum to EGR valve
at idle.
Sticky EGR valve
EGR valve vacuum hose mis-
routed.
Loose EGR attaching bolts
Sticky or binding EGR valve.
EGR modulator valve blocked
or air flow restricted.
Wrong or no EGR gasket.
EGR modulator valve blocked
of air flow restricted.
Restriction in EGR vacuum line.
VSV filter plugged.
Sticking or binding EGR valve.
EGR modulator valve blocked
of air flow restricted.
Insufficient exhaust gas recircu-
lation flow during part throttle
accelerations.
Correction
Check EGR valve vacuum hose routing.
Correct as required.
Check EGR valve for correct operation.
Check EGR attaching bolts for tightness.
If no loose, remove EGR valve and inspect
gasket.
Check vacuum from carburetor EGR port with
engine at stabilized operating temperature and
at idle speed.
Check EGR valve for correct operation,
Check EGR valve vacuum hose routing.
Correct as required.
Torque bolts.
Same as listing in "Engine idles Abnomrally
Rough and/or Stalls" condition.
Clean EGR passage deposits.
Perform EGR System Check.
Check EGR modulator valve operation.
Install new gasket, torque attaching parts.
Check EGR modulator valve operation.
Check EGR vacuum lines for kinks, bends, etc.
Remove or replace hoses as required.
Check VSV for correct operation.
Check EGR valve for excessive deposits causing
sticky or binding operation.
Check internal control valve operation.
Check EGR valve hose routing. Check EGR
valve operation. Repair or replace as required.
Replace valve as required. Check EGR passages
and valve for excessive deposit.
Clean as required. Check VSV operation.