Compression Question...

[Parmas]

*For d ones who don't know* I own a yaris 2001 with a 1NZFE turbo engine.

I had seen many threads showing built 1NZFE engines for turbo through out my research and I noticed that many of them use CP pistons or other brands with a compression ratio of 9.5:1.

Well mine seems to be the only 1NZ with 8.5:1 compression arias pistons...

From the beginning of my project I always had\have issues in slow running and idling so I am suspecting if these issues might be due to the lower compression :iono:

[yaris-me]

What happens if you raise you idle a little? Maybe you have other issues, like valve problems?

[cali yaris]

mine are 9:1 -- I'm pretty sure. Your car should idle ok.

[Parmas]

What happens if you raise you idle a little? Maybe you have other issues, like valve problems?

Idle is fluctuating between 1000rpm till 1500rpm especially when cold starting. Sometimes it reach 1800rpm so we didn't try to raise idle since its already too much for me.

When slowly pushing the gas from 2000 till 3000rpm, the engine knocks several times. After 3k rpm kicks in VVTI & boost and the engine shows us real performance till 6500rpm.

I know some should say it's a tuning problem and maybe it is... but it's really hard to get it stable within 2K-3K rpm range especially when you try to lean it out more than 10.5 AFR