Navistar MaxxForce 9 - Page 88

DIAGNOSTICMANUAL
WARNING
Topreventpersonalinjuryordeath,donotexceedlocalspeedlimitlawsordrivetoofast
forconditionswhenperformingLugDownTest.
Step
ActionDecision
2A
UsingEST ,gotoSessions>Performance.Findanopen
stretchofroadinordertoperformLugDownT est.When
drivingconditionsaresafe,selecttherecordsnapshoticon
fromthetoolbar,andperformLugDownprocedurebelow:
1.Selectasuitablehighrangegear(Example:Ina
10speedgearbox,selectthe8thspeed).
2.Allowenginespeedtodropto1000rpm.
3.Pressacceleratorpedalfullytotheoor,and
acceleratetoratedenginespeed.
AfterLugDownT estiscomplete,stoprecordingandsave
snapshot.
Gotostep2B
Step
ActionDecision
2B
Checkforlowfuelrailpressure.UsingESTwithServiceMaxx™
software,usetheplaybackfeatureandgraphthefollowing
signalvaluesfromLugDownT est:
SignalValues:
•EngineSpeed
•FuelRailPressure(FRP)
•FuelRailPressureDesired(FRPD)
ComparesnapshottoGraph3andassociatedGraphAnalysis
page124.
IsFRPsignaloperatingasperGraph3GraphAnalysis?
Yes:Gotostep2C
No:Diagnoseandrepairlowfuel
railpressure(SeePerformance
DiagnosticssectioninEngine
DiagnosticManual).Afterrepairs
arecomplete,retestfororiginal
problem.
84
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