It must be nerve-wracking to use a fake passport at a border crossing.
Some fake passports are completely fake, and are not registered in the "issuing" country's database. They will be rejected when scanned at any airport and border crossing.
Other fake passports were authentic, but were stolen. These MIGHT scan, but you never know when the issuing country will report them as stolen, at which point suddenly they won't scan. In any event, they will expire and you won't be able to renew them.
Which type of passport would you be given? You won't know until you try at the border, and as PMM says, you might find yourself in jail.