Your firmware is too old. Install custom firmware (CFW) 6.60 or 6.61. Use Infinity 2.0 for permanent CFW.
While highly compressed files save significant storage space, they introduce specific hardware bottlenecks on the PSP: CPU Overhead: Tekken 3 Psp Iso Highly Compressed
Since the PSP has built-in backwards compatibility for PS1 games, a properly compressed Your firmware is too old
Because Tekken 3 was originally released on CDs with a capacity of roughly 650MB, the file size was manageable for its time. However, the rise of "highly compressed" files was driven by internet speeds of the mid-2000s and the limited storage capacity of early Memory Stick Duo cards. Gamers sought ways to shrink a 500MB+ game into a file often under 100MB or even 50MB. Tekken 3 Psp Iso Highly Compressed