Jerking on high revs, What the hell? Need ur help angels:( Options

[Rav4Race]

Hi broz/sis.

Engine: 3SGTE ST-205

On first gear i can rev fully to 7k with no problem.
On second, i can rev to about 6.6k coz it starts to jerk a bit.
On 3rd gear, the jerks start as from 5.6k:(
4th....5k:(
No need to tell u about 5th gear:(

What can it be? Anyone of u got this kind of problem in the past?
Can it be the spark plugs? i got iridium denso on it (IK20) i ran only like 20,000km with it.
Can it be the spark plug wires? I have the OEM wires which ran only 90,000kms.
Can it be the fuel system? To start with Fuel pump? I have the Walbro 255lph fitted some months ago.
Injectors? Used an injector cleaner recently but nothing has changed (unless i have to change the cleaner itslef:()
BTW CAN SOMEONE TELL ME WHICH % OF FUELING IS OK AT IDLE for injectors? ACTUALLY AM AT ABOUT 90%.

Is it the boost? Am boosting to a max of 1.1 bar (about 17psi) sometimes it hit 1.15bar. I lowered the boost recently but the problem still persist.

Is it evil? Havent met the priest the past 2years:-/ plz help...what can it b? what should i do? I can't race correctly with this bump...

[silver6gc]

Rav4Race Posted Today, 07:06 AM
ok will try some more injector cleaners. i forgot to add, when i get this jolt black smoke come off my exhaust...is that normal?

Black smoke is unburned fuel, you're still getting fuel, it's your ignition thats cutting out. Either the ECM is fully retarding ignition timing for some reason (somebody said knock sensor earlier) or your ignition system itself has a problem. When the ECM hits any type of limiter, be it for boost or revs or anything like that, it should cut out fuel not ignition. No ECM has EVER been programmed from the factory to dump raw fuel down the exhaust, that would just be dumb.

This post has been edited by silver6gc: Jan 14, 2009 - 9:55 PM