Suzuki Samurai 1986, Service Manual

Page: 168 / 482

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