1DIAGNOSTICTROUBLESHOOTINGPROCEDURES35
Step3Recordsnapshotofenginerunningdataanddetermineifengineidlesproperly.Decision
Yes:Goto4.1RoughIdle
(page66).
PerformRecordSnapshotofEngineRunningData(page2113)whilesymptomisoccurring.
A.Runengineatidle.
B.Fullthrottlefor15seconds.
C.Idlefor30seconds.
D.Fullthrottlefor15seconds.
E.Idlefor30seconds.
F.Stoprecording.
Doesengineidleroughorsurgeatidle?
No:GotoStep4.
Step4Determineifengineisabletoreachratedspeed.Decision
Yes:GotoStep5.A.Startengine.
B.Increaseenginerpmtoratedspeed,andreturntoidle.
Isengineabletoreachratedspeed?
No:Goto4.2Engine
UnabletoReachRated
Speed(NoLoad)(page
70).
Step5Determineifapoppingnoiseiscomingfromengineairintake.Decision
Yes:Goto4.3Popping
NoisefromIntake(page
72).
A.Startengine.
B.Listenforpoppingnoisefromengineairintake.
C.Increaseenginerpmtoratedspeedandreturntoidle.
Ispoppingnoiseheardfromengineairintake?
No:Reviewoperator
complaint.