My evo 8 has been jerking at 150kph, once in a while sputters even at low speed WOT..
So i replaced plugs, coil packs and cables but still this problem has not yet been solved,

the car smells gas on the engine bay after a bit of spirited driving, where do i check next?
could the gas smell be related to the jerking problem?

 

Un educated guess but it could be a boost leak from a connection point between intercooler pipes. Follow the fuel feed and return line inspect for cracks/leaks.

 

An injector seal that's split.

 

tightened all the clamps, jerking still persists..
i can hear a faint whistle from time to time under boost.. ill get a proper boost leak test done soon..

 

Fixed the issue.
Problem was a clogged fuel filter.

 

You mean it cleared after the ECU got reset?

 

what are you talking about?
Anyway, the jerking came back

 

Well of course it came back.

Try resetting the ECU again?

 

Did you find fuel leak?
It could be alot of different things.
Can you log when it occurs?
Is it a misfire?
Or is it a sputter?
Could be a tps sensor.

 

what are you talking about resetting the ecu, are u confusing this thread with another or what?

 

Okay my wideband says the car is running rich, at wide open throttle it goes upto 10.0afr which is the richest the gauge can read, pretty sure it hits the 9s,

its more like a hesitation feel,
throttle position looks perfectly okay according to the logs,

tomorrow im getting a boost leak test done..

 

Yea thats real rich. What is your fuel trims at? And what is your 02 sensor feed back at idle? Likely a boost leak.

 

havent logged fuel trims but fuel pressure seems okay since im getting a rich condition, havent logged o2 sensor feedback since i was told that would bring a check engine light if its spoilt,

did a boost leak test, found a massive hole in the intercooler, got it welded properly,
apparently the jerking is still there.