21
EngineControlLinkagesGASOLINEVEHICLE-FUELSYSTEM
CLOSEDTHROTTLEORIDLEADJUSTMENT–PEDAL-STARTVEHICLES
Whentheacceleratorpedalisreleased,theenginewillstop.Therefore,itisnotpossibletomeasureorsetidling
speedundernormalvehicleoperatingconditions.Setthrottlevalveasfollows:
1.Loosenthethrottlebodyidlescrewsothatitisnottouchingthethrottlelever(Figure21-8,Page21-12).
2.Slowlytightentheidlescrewuntilitlightlytouchesthethrottlelever,thentightenitanadditional1wholeturn
(360degrees).
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Figure21-8IdleScrew
HOWTOMEASUREGROUNDSPEED
BestMethod
AneasywaytocheckgroundspeedisbyusingaGPSdeviceorsmartphoneapplication(app).Ifthesearenot
available,usethealternatemethodbelow.
AlternateMethod(Calculated)
Groundspeediseasilydeterminedbyaknowndistancetravelled,dividedbytheamountoftimeittooktotravelthat
knowndistance(Rate=Distance/Time).
1.Establishaknowndistancetotravel(example:100ft.(30.5m)inasafelocationusingconesorothertypeof
marker.
2.Drivevehicleandbringtomaximumspeedbeforereachingtherstcone.
3.Usingastopwatch,recordtheamountoftimeittakestotravelfromtherstconetothesecondconeatmaximum
speed.
4.Withdistanceandtimedetermined,calculategroundspeed:
4.1.Rateinseconds:Dividedistance(100ft(30.5m))bytime(5seconds)=20ft/sec(6.1m/sec).
4.2.Convertsecondstohour:Multiply20ft/sec(6.1m/sec)by3600(thenumberofsecondsinanhour)=
72000ft/hour(21960m/hour)
4.3.ConverttoMPH:Divide72000ft/hourby5280(numberofftin1mile)=13.64miles/hour
ConverttoKPH:Movethedecimalpointoverthreeplaces;21960m/hour=21.96km/hour
Page21-122019PrecedentVillager2MaintenanceandServiceManual