AUTO ENGINES UNIT 5 QUESTIONS
WITH COMPLETE ANSWERS
Fuel ppis ppgenerally ppavailable ppin ppoctane ppratings ppof ppall ppof ppthe ppfollowing
ppEXCEPT:
a. pp87 ppoctane
b. pp89 ppoctane
c. pp92 ppoctane
d. pp99 ppoctane pp- ppAnswer ppd. pp99 ppoctane
Normal ppcombustion pptakes ppapproximately:
a. ppThree ppmilliseconds
b. ppThirty ppmilliseconds
c. ppTwo ppnanoseconds
d. ppTwo ppnanoseconds pp- ppAnswer ppa. ppThree ppmilliseconds
Misfire ppmeans:
a. ppThe ppcylinder ppfires ppat ppthe ppwrong pptime.
b. ppThe ppcylinder ppdoes ppnot ppfire.
c. ppTwo ppsparks ppoccur.
d. ppThe ppwrong ppspark ppplug ppis ppinstalled. pp- ppAnswer ppb. ppThe ppcylinder ppdoes
ppnot ppfire.
Each ppof ppthe ppfollowing ppis ppa pplikely ppcause ppof ppdetonation ppEXCEPT:
a. ppCarbon ppbuildup ppin ppthe ppcombustion ppchamber
b. ppEngine ppoverheating
c. ppA pplean ppair-fuel ppmixture
d. ppFuel ppwith pptoo pphigh ppof ppan ppoctane pprating pp- ppAnswer ppd. ppFuel ppwith pptoo
pphigh ppof ppan ppoctane pprating
A pp_______________ ppinforms ppthe ppPCM ppabout ppunusual ppfrequency ppvibrations
ppin ppthe ppengine.
a. ppCoolant pptemperature ppsensor
b. ppVibrator ppactuator
c. ppKnock ppsensor
d. ppPCM ppmounting ppsensor pp- ppAnswer ppc. ppKnock ppsensor
Technician ppA ppsays ppthat ppworn pppiston pprings ppcan ppcause ppa pplack ppof pppower.
ppTechnician ppB ppsays ppthat ppa ppburned ppvalve ppcan ppcause ppa pppopping ppnoise
ppout ppof ppthe ppintake ppor ppexhaust. ppWho ppis ppcorrect?
a. ppA pponly
,b. ppB pponly
c. ppBoth ppA ppand ppB
d. ppNeither ppA ppnor ppB pp- ppAnswer ppc. ppBoth ppA ppand ppB
Spark ppignition ppoccurs:
a. ppATDC ppon ppthe pppower ppstroke
b. ppATDC ppon ppthe ppcompression ppstroke
c. ppATDC ppon ppthe ppintake ppstroke
d. ppBTDC ppon ppthe ppcompression ppstroke pp- ppAnswer ppd. ppBTDC ppon ppthe
ppcompression ppstroke
Technician ppA ppsays ppthat pphydrocarbon ppemissions pptypically ppincrease ppwhen ppan
ppengine ppmisfires. ppTechnician ppB ppsays ppthat pplow ppcompression ppcan ppcause
ppmisfire. ppWho ppis ppcorrect?
a. ppA pponly
b. ppB pponly
c. ppBoth ppA ppand ppB
d. ppNeither ppA ppnor ppB pp- ppAnswer ppc. ppBoth ppA ppand ppB
Too pplow ppa ppfuel ppvolatility ppused ppin ppthe ppwinter ppwill ppcause:
a. ppExcessive ppevaporative ppemissions
b. ppHard ppstarting ppand pprough pprunning ppwhen ppcold
c. ppExtended ppcranking pptimes ppwhen ppthe ppengine ppis pphot
d. ppDetonation pp- ppAnswer ppb. ppHard ppstarting ppand pprough pprunning ppwhen ppcold
A ppburned ppintake ppvalve ppwill ppcause:
a. ppWeak ppengine ppvacuum
b. ppLower ppcompression pppressures
c. ppReduced ppengine pppressure
d. ppAll ppof ppthe ppabove pp- ppAnswer ppd. ppAll ppof ppthe ppabove
A ppleak pppast ppthe pp________ ppcan ppcause ppcompromised ppengine ppperformance.
pp- ppAnswer pphead ppgasket
The pp
________, pp________ pp, ppand pp________ ppin ppaddition ppto ppthe ppspark ppplug ppand
ppcylinder ppwall ppseal ppthe ppcombustion ppchamber. pp- ppAnswer ppvalves, pppiston
pprings, pphead ppgasket
Malfunctions ppin ppthe pp__________ ppsystem ppand ppthe pp________ ppsystem ppcan
ppcause ppengine ppmechanical ppproblems. pp- ppAnswer pplubrication, ppcooling
Three pptypes ppof ppabnormal ppcombustion ppare pp
_______,_________ pp, ppand pp_________ pp. pp- ppAnswer ppdetonation, pppreignition,
ppmisfire
, The ppfiring ppvoltage ppof ppthe ppspark ppplug ppis ppdependent ppon ppall ppof ppthe
ppfollowing, ppEXCEPT:
a. ppAir/fuel ppratio
b. ppTurbulence
c. ppCylinder pppressure
d. ppVehicle ppspeed pp- ppAnswer ppd. ppVehicle ppspeed
The ppspark ppline pprepresents:
a. ppThe ppvoltage pprequired ppto ppjump ppthe ppspark ppplug ppgap.
b. ppThe ppvoltage ppneeded ppto ppovercome ppall ppsecondary ppignition ppsystem
ppresistances.
c. ppThe ppvoltage ppneeded ppto ppsustain ppthe ppspark ppacross ppthe ppspark ppplug ppgap.
d. ppThe ppreserve ppcapacity ppof ppthe ppcoil. pp- ppAnswer ppc. ppThe ppvoltage ppneeded
ppto ppsustain ppthe ppspark ppacross ppthe ppspark ppplug ppgap.
Typical ppfiring ppline ppvoltage ppis ppbetween pp8,000 ppand pp60,000 ppvolts.
a. ppTrue
b. ppFalse pp- ppAnswer ppa. ppTrue
All ppof ppthese pphave ppto ppdo ppwith ppan ppengine pprelated ppvibration ppexcept:
a. ppAn ppinsulator
b. ppA pptransmission pproute
c. ppA ppsource ppof ppvibration
d. ppAn pposcillator pp- ppAnswer ppa. ppAn ppinsulator
During ppwhat ppconditions ppcan ppa ppnoise ppoccur?
a. ppAt ppcertain pptemperatures
b. ppAt ppcertain ppengine ppspeeds
c. ppAt ppcertain ppengine pploads
d. ppAny ppof ppthese pp- ppAnswer ppd. ppAny ppof ppthese
Which ppof ppthe ppfollowing ppis ppthe ppfirst ppstep ppin ppdiagnosing ppan ppengine
ppvibration ppor ppnoise?
a. ppGathering ppinformation ppfrom ppthe ppcustomer.
b. ppReplacing ppthe ppcrankshaft ppdamper
c. ppPerforming ppa ppcylinder ppbalance pptest
d. ppChecking ppengine ppmounts pp- ppAnswer ppa. ppGathering ppinformation ppfrom ppthe
ppcustomer.
A ppspark ppplug ppgap ppthat ppis pptoo ppwide ppcan ppcause:
a. ppValvetrain ppclatter
b. ppMisfire
c. ppDetonation
d. ppLow ppcompression pp- ppAnswer ppb. ppMisfire
WITH COMPLETE ANSWERS
Fuel ppis ppgenerally ppavailable ppin ppoctane ppratings ppof ppall ppof ppthe ppfollowing
ppEXCEPT:
a. pp87 ppoctane
b. pp89 ppoctane
c. pp92 ppoctane
d. pp99 ppoctane pp- ppAnswer ppd. pp99 ppoctane
Normal ppcombustion pptakes ppapproximately:
a. ppThree ppmilliseconds
b. ppThirty ppmilliseconds
c. ppTwo ppnanoseconds
d. ppTwo ppnanoseconds pp- ppAnswer ppa. ppThree ppmilliseconds
Misfire ppmeans:
a. ppThe ppcylinder ppfires ppat ppthe ppwrong pptime.
b. ppThe ppcylinder ppdoes ppnot ppfire.
c. ppTwo ppsparks ppoccur.
d. ppThe ppwrong ppspark ppplug ppis ppinstalled. pp- ppAnswer ppb. ppThe ppcylinder ppdoes
ppnot ppfire.
Each ppof ppthe ppfollowing ppis ppa pplikely ppcause ppof ppdetonation ppEXCEPT:
a. ppCarbon ppbuildup ppin ppthe ppcombustion ppchamber
b. ppEngine ppoverheating
c. ppA pplean ppair-fuel ppmixture
d. ppFuel ppwith pptoo pphigh ppof ppan ppoctane pprating pp- ppAnswer ppd. ppFuel ppwith pptoo
pphigh ppof ppan ppoctane pprating
A pp_______________ ppinforms ppthe ppPCM ppabout ppunusual ppfrequency ppvibrations
ppin ppthe ppengine.
a. ppCoolant pptemperature ppsensor
b. ppVibrator ppactuator
c. ppKnock ppsensor
d. ppPCM ppmounting ppsensor pp- ppAnswer ppc. ppKnock ppsensor
Technician ppA ppsays ppthat ppworn pppiston pprings ppcan ppcause ppa pplack ppof pppower.
ppTechnician ppB ppsays ppthat ppa ppburned ppvalve ppcan ppcause ppa pppopping ppnoise
ppout ppof ppthe ppintake ppor ppexhaust. ppWho ppis ppcorrect?
a. ppA pponly
,b. ppB pponly
c. ppBoth ppA ppand ppB
d. ppNeither ppA ppnor ppB pp- ppAnswer ppc. ppBoth ppA ppand ppB
Spark ppignition ppoccurs:
a. ppATDC ppon ppthe pppower ppstroke
b. ppATDC ppon ppthe ppcompression ppstroke
c. ppATDC ppon ppthe ppintake ppstroke
d. ppBTDC ppon ppthe ppcompression ppstroke pp- ppAnswer ppd. ppBTDC ppon ppthe
ppcompression ppstroke
Technician ppA ppsays ppthat pphydrocarbon ppemissions pptypically ppincrease ppwhen ppan
ppengine ppmisfires. ppTechnician ppB ppsays ppthat pplow ppcompression ppcan ppcause
ppmisfire. ppWho ppis ppcorrect?
a. ppA pponly
b. ppB pponly
c. ppBoth ppA ppand ppB
d. ppNeither ppA ppnor ppB pp- ppAnswer ppc. ppBoth ppA ppand ppB
Too pplow ppa ppfuel ppvolatility ppused ppin ppthe ppwinter ppwill ppcause:
a. ppExcessive ppevaporative ppemissions
b. ppHard ppstarting ppand pprough pprunning ppwhen ppcold
c. ppExtended ppcranking pptimes ppwhen ppthe ppengine ppis pphot
d. ppDetonation pp- ppAnswer ppb. ppHard ppstarting ppand pprough pprunning ppwhen ppcold
A ppburned ppintake ppvalve ppwill ppcause:
a. ppWeak ppengine ppvacuum
b. ppLower ppcompression pppressures
c. ppReduced ppengine pppressure
d. ppAll ppof ppthe ppabove pp- ppAnswer ppd. ppAll ppof ppthe ppabove
A ppleak pppast ppthe pp________ ppcan ppcause ppcompromised ppengine ppperformance.
pp- ppAnswer pphead ppgasket
The pp
________, pp________ pp, ppand pp________ ppin ppaddition ppto ppthe ppspark ppplug ppand
ppcylinder ppwall ppseal ppthe ppcombustion ppchamber. pp- ppAnswer ppvalves, pppiston
pprings, pphead ppgasket
Malfunctions ppin ppthe pp__________ ppsystem ppand ppthe pp________ ppsystem ppcan
ppcause ppengine ppmechanical ppproblems. pp- ppAnswer pplubrication, ppcooling
Three pptypes ppof ppabnormal ppcombustion ppare pp
_______,_________ pp, ppand pp_________ pp. pp- ppAnswer ppdetonation, pppreignition,
ppmisfire
, The ppfiring ppvoltage ppof ppthe ppspark ppplug ppis ppdependent ppon ppall ppof ppthe
ppfollowing, ppEXCEPT:
a. ppAir/fuel ppratio
b. ppTurbulence
c. ppCylinder pppressure
d. ppVehicle ppspeed pp- ppAnswer ppd. ppVehicle ppspeed
The ppspark ppline pprepresents:
a. ppThe ppvoltage pprequired ppto ppjump ppthe ppspark ppplug ppgap.
b. ppThe ppvoltage ppneeded ppto ppovercome ppall ppsecondary ppignition ppsystem
ppresistances.
c. ppThe ppvoltage ppneeded ppto ppsustain ppthe ppspark ppacross ppthe ppspark ppplug ppgap.
d. ppThe ppreserve ppcapacity ppof ppthe ppcoil. pp- ppAnswer ppc. ppThe ppvoltage ppneeded
ppto ppsustain ppthe ppspark ppacross ppthe ppspark ppplug ppgap.
Typical ppfiring ppline ppvoltage ppis ppbetween pp8,000 ppand pp60,000 ppvolts.
a. ppTrue
b. ppFalse pp- ppAnswer ppa. ppTrue
All ppof ppthese pphave ppto ppdo ppwith ppan ppengine pprelated ppvibration ppexcept:
a. ppAn ppinsulator
b. ppA pptransmission pproute
c. ppA ppsource ppof ppvibration
d. ppAn pposcillator pp- ppAnswer ppa. ppAn ppinsulator
During ppwhat ppconditions ppcan ppa ppnoise ppoccur?
a. ppAt ppcertain pptemperatures
b. ppAt ppcertain ppengine ppspeeds
c. ppAt ppcertain ppengine pploads
d. ppAny ppof ppthese pp- ppAnswer ppd. ppAny ppof ppthese
Which ppof ppthe ppfollowing ppis ppthe ppfirst ppstep ppin ppdiagnosing ppan ppengine
ppvibration ppor ppnoise?
a. ppGathering ppinformation ppfrom ppthe ppcustomer.
b. ppReplacing ppthe ppcrankshaft ppdamper
c. ppPerforming ppa ppcylinder ppbalance pptest
d. ppChecking ppengine ppmounts pp- ppAnswer ppa. ppGathering ppinformation ppfrom ppthe
ppcustomer.
A ppspark ppplug ppgap ppthat ppis pptoo ppwide ppcan ppcause:
a. ppValvetrain ppclatter
b. ppMisfire
c. ppDetonation
d. ppLow ppcompression pp- ppAnswer ppb. ppMisfire
