are u talking abt carburater engines or efi?? cz all of the mehran have carburater engine but not all corollas are carburaters,,specially local made,,,toyota indus launch 1st efi car in 1995,,,GLI 1.6....i think soo...
and if cng wiring is not correctly done then it doesnt give proper current for sparking,,, some time it start supllying more current and some time low current,,,in both cases engine light gets on