Are you using an A/T ECU?

 

Yess I am, but it has the neutral bypass thing done.

 

Now Im starting to get a small misfire on idle.
-_-"

 

Then it's definitely the coilpacks

 

have you tried a copper sparkplug with a tight gap... like .024 or .026?

since your running stock boost (9psi) i would get a set of NGK BKR6E's they run ~$2/pc at oreillys

if you get to a point where you want to run more boost switch to a heat range 7 BKR7E

 

ok. sounds good, I will try those plugs out
What exactly do the heat ranges help the spark do. Will running colder plugs give me something while running hoter plugs give me something else.

 

how long have you had this 1jz??
the closed loop for an ecu is up to about 4-5k -- which is where you state the car starts to hesitate.. but when you check your plugs.. they are all black and sooty.. which could indicate the vehicle is being flooded/running rich.
Id almost want to guess you have larger injectors in there and without any engine management when the ecu goes into open loop.. it doenst have the ability to compensate for the larger injectors and therefore you are running extremely rich..

but if youve had the 1j for a long while and this problem didnt exist before but it does now.. then thats most definately not the problem.

 

no I have only had the 1j in my possession for about 3 months. I do not have bigger injectors and am running stock ecu.

How does a open/closed loop work. ? Is there a solution to it?

 

that will give you a good idea what closed vs open is/means.

http://www.enginebasics.com/EFI%20Tu...Loop%20o2.html

once you get things sorted out, and you are still running stock, use the plugs designed for the car.

DENSO Toyota Part number 90919-01180 ＰＫ２０Ｒ８
NGK Toyota Part Number 90919-01181 ＢＫＲ６ＥＰ－８
or anything as such the same as the above ^ try not to go colder or hotter or with a different gap, as you said your running stock - and theres no need to change anything with the pregapped plugs the motor was designed to run on.

As for your problem, I can only assume its the coil pack or you dont have a plug actually connected all the way. you really gotta push em back in.

 

A "colder" plug literally dissipates heat better than a "hot" plug. You want to match the heat range with the temperature your engine is going to see.

The danger of running a plug too hot is pre ignition and detonation becuase the spark plug gets too hot and can't dissipate the heat.

The danger of running a plug too cold is bad ignition while getting the car warmed up.

Toyota calls for a heat range 6 plug for the stock 8.5:1 compression ratio and 9psi. If you increase your boost you effectively raise the compression ratio which raises the temps, so you want to run a colder plug to prevent the plug from getting too hot and causing preignition/det

 

The Auto ECU should pull timing to soften a shift. This should feel like a hesitation / power loss. Furthermore the phenomenon disappearing when you shift gears would support this.

 

Im try another ecu soon. And See whats up with the plugs. I had someone suggest seafoam. Anyone shedding some light on this?

 

Don't try another ECU. It's a waste of time. They are identical except the A/T control is integrated into the case. As far as engine function they are identical.

The A430 A/T trans is electronically controlled. This means there is no engine ECU "Timing Dip", because the Trans has it's own control. It doesn't need the Engine ECU to do anything except run the engine.

Just make sure you have NGK coppers, NOT Iridiums, gapped to stock, and make sure that your Ignition is up to par.

It sounds like fuel cut, but if your plugs are black your ignition is not running the way it needs to. Get it all up to stock again.

 

Bringing this bad boy back, I'm having the same exact issue. Did this ever get resolved???

FUEL FILTER REPLACED
NEW FUEL PUMP
NEW SPARK PLUGS GAPPED TO .026
REPLACED THE COIL PACKS ALTHOUGH STILL OLD ONES
FUEL CUT DEFENDER

Any input highly appreciated