it is a PKDM vehicle made in Pakistan.
visit a workshop in your county which can perform compression test. Mechanics always suggest a short cut to make money from scrapyards and from customers. scrapyard engines are highly unreliable.
Engine overhaul parts are available brand new with automotive spare parts sellers, search in your town there must a shop selling daihatsu / toyota oem new parts. Rebuild the engine.
you can very well read over this forum 660 JDM engines does not have new spare parts available to rebuild, therefore swap is only choice for 660 jdm users.
It is also a myth that JDM 660 engine has high fuel efficiency i.e TORKHAM to GAWADER per litre.