iiplagi ze-spark, ezaziwa ngokuba ziiplagi zomlilo, ziya kusebenza njenge-pulse ye-high-voltage piezoelectric discharge evela kwi-high-voltage lead (iplagi yomlilo), eya kuphula umoya phakathi kwee-electrodes ze-spark plugs, ukuvelisa iintlantsi zombane ukuze zilume. umxube wegesi kwi-cylinder.Iimeko ezisisiseko ze-injini yokusebenza ephezulu: i-spark ephezulu ezinzileyo yamandla, umxube ofanayo, umlinganiselo ophezulu woxinzelelo.Iimoto ezineenjini zokutsha zangaphakathi zisebenzisa i-petroli kunye ne-diesel fuel.Kwimarike yemoto yaseTshayina, iimoto zepetroli zithatha indawo enkulu.Iinjini zepetroli zahlukile kwiinjini zedizili ngenxa yokuba i-petroli inendawo ephezulu yokutshisa (emalunga nama-400 degrees), nto leyo efuna ukunyanzeliswa komlilo ukutshisa umxube.Ngokukhutshelwa phakathi kwee-electrodes ukuvelisa iintlantsi, i-injini yepetroli isetyenziselwa ukutshiswa kwamafutha kunye negesi ngexesha elifanelekileyo ukuvelisa amandla, kodwa njengepetroli yamafutha nakwindawo yobushushu obuphezulu kunzima ukutsha okuzenzekelayo, ukwenzela ukuba ukutsha kwayo kwangethuba ku kuyimfuneko ukusebenzisa "umlilo" ukuvutha.Apha ukuvutha kwentlantsi ngumsebenzi we "spark plug".