2JZ Piston Pitting Or (Knocked Issue)

Hello everyone,

Below are the specs of the engine

2JZ GTE VVTI Stock Long block with some upgrades

CAMS : 264

Turbo: AR70 Journal bearing

Boost Pressure: 1.5 Bar

Spark Plugs : NGK BKR7E

Fuel : RON 97

Piston: Thailand Made Stock 2JZ Pistons

ECU : LINK Storm G4+

Timing Table :[img="blob:https://www.hpacademy.com/36c2d18f-94c7-4c7a-a3d7-96966361981d" alt=""]

TPS vs RPM

The Max RPM limit is set to 7.5K

After A little three months of engine running

We open engine a apart for some upgrades we notice that there is pitting on the pistons on the exhaust side.

Wondering is it piston is not genuine or there is a problem with my timing table, do think that the numbers in the table are very very minimum?

Did check for Knocked with Links knock equipment, no sign's of knock.

Wondering which part went wrong that cause the issue.

For fueling AFR is around 10.5 at WOT, engine make 354 WHP

Already did check for timing drift there are no signs of it drift from 1.5K RPM to 4K.

This have been hunting me for the past week, hope that you guys can shine a light on me.

G'day Chyuan. Can you post the picture of your timing table as an attachment, I can't get your link to open. If you could pop up a picture of the pistons too that'd be ace :-).

Is the fuel in Malaysia pretty good quality? What I mean, is if you purchase 97 RON, is it pretty consistent?

Hi Andy,

After much investigation, the pitting issue is only on the last piston.Which its a knocking issue. From the photo its seems like all of them have pitting issues, but after they totally pull out all the piston its only one that is doing it.

The culprit is a bad injector, we send it in for volume flow check, the last Unit is lack of fuel if compare to the others.

We are pretty sure about the compression ratio, as the head is dead stock. No skimming have been done to it.

The stock coils are not going to cut, after last Dyno session one of them are pretty dead.

We are upgrading to Yaris Smart coils.

I have cross check the dwell time and it seems where it should be.

Have also change the timing table Axis to MAP VS RPM.

May I know how much ignition advance at 1.5bar of boost is consider aggressive. I do understand it comes down to fuel quality, compression ration and other factors. Do you have a ball park number that at least could give me an idea to judge ?

I am also finding ways to detect knock and respond to it in a more sensitive way. I does not detect or notice any knocked during the Dyno run. Do you any suggestion ? I am using Link knockblock.