1jz 1/4 throttle same as full throttle?

[naten]

for future refernce dont use blue thread locker on idle screws

its not easy to move

got the shits with it.

I left the idle screw where it was and adjusted the tps so that the idle clicks off at 0.75mm gap

Going for a spin now with the gtech

[naten]

ma61+1jz+gtech+rain= not good

ok idle is pretty much ok now its still a little low (600rpm) but atleast its not cutting out.

Nothing really changed hesitation is still there though it does seem the slightest bit better on the throttle (as in full does more then 1/4). The problem is still there though and is quite pronounced.

Dyno should reveal some more info tomz

[Wildsupra]

ok havent read the whole thread so excuse me if this has already been mentioned, have you got the traction control butterfly in the throttle body? if so is it stuck at 1/4 oping by any chance? cos if it is then no matter wot you do with the foot throttle you wont get any more flow than whatever the traction butterfly is open at.

[Norbie]

Agree with the above. This doesn't sound like a tuning problem, the only way this could really happen is if there's some big restriction somewhere in the inlet system which makes the last 75% of throttle opening redundant. It could be the trac butterfly or something else, like a blocked intercooler perhaps? Actually even a blocked exhaust (eg collapsed cat) might cause similar issues.

[naten]

Im pretty sure i dont but i may be wrong. There is only one butterfly and that has the TPS on one side and the throttle cable/linkage on the other.

It looks like this one:
http://wwwrsphysse.anu.edu.au/~amh11...kC_1JZ-GTE.jpg

Its been the same through 2 different intercoolers so i dont believe they were both blocked. They were both cleaned too.

The cat i can check myself just by pulling it out and having a look yea? Was a cheapy at the time so it is possible i guess.

I still have this hunch that the hesitation is fuel pressure related.

Ill hopefully know more tommorrow, ill keep yas posted.

Oh btw thanks for the help guys

[Wildsupra]

well according to that pic there is no traction control butterfly so that counts that out.
Block cat would normally equal very low power, it seems your still describing good power?
Check it to be sure, also check that you are actually getting full throttle with the pedal.
Is this a sudden new prob or has it always been like this?

I also doubt its fuel related as if 1/4 to full throttle makes no difference your engine would prolly blow if it was fuel leaning out that much.

Matty

[Wildsupra]

one other question how much boost does it make at 1/4 throttle? and how much at full throttle? does it vary between the 2? If not i'd say ya wastegate might be leaking/stuck open.....or ya factory BOV is jammed open causing the pressure to vent back into air filter intake.
Once again excuse me if this has been mentioned still havent had time to read whole thread.

[naten]

Im really glad i chose to go this morning....

Dyno chart here:


Anyone guess whats wrong here? Its so piss lean its not funny. Basically once it starts making boost it leans out and keeps heading leaner. Starts around 14:1 he stopped when it was heading towards 17.5:1

Its very scary that the car would of been like that for the last 100,000k and ive done heaps of thrashing etc in that time too

I bought a walbro on the spot and will put it in this arvo or tommorrow.

I believe this will be the cause of my hesitation and 1/4 -> full throttle feeling.

Just angry at myself i didnt get the car dynoed earlier!

[wilbo666]

Edit: I'm silly

But on that note choosing a full scale value of 270kw when it made 75 is silly

Cheers
Wilbo

[Enigma-Penguin]

It looks fine to me wilbo , 30 kw to about 75kw with the afr starting at just under fifteen and climbing...

well not fine, but you get what I mean ...

[wilbo666]

It looks fine to me wilbo , 30 kw to about 75kw with the afr starting at just under fifteen and climbing...

well not fine, but you get what I mean ...

Oh I'm just an idiot I read it the other way around

Cheers
Wilbo

[CrUZida]

The only thing i cannot figure out is where to set the idle stop screw to start with. As in how much it should be opened to before adjusting and taking measurements etc

Are you talking about the screw that determines how far the throttle plate is open when your foot is off the pedal?

If so, the throttle plate is supposed to be 100% closed at that time.
With the throttle plate closed, and the TPS in IDL, the ECU will regulate the idle RPM with the ISCV.
You'll probably have to readjust the TPS after closing the throttle plate though, otherwise you'll experience bad idle and stalling again.

Set IDL to open when the throttle is just cracked a mm or so. Ignore all the other things to do with the TPS. IDL is the only important one. (assuming you've verified that the TPS is working correctly)

[naten]

Cruzida:

Yea thats exactly what i was talking about thanks

I get how to do the rest of the adjusting i just didnt know where to put the throttle to start with. Im going to just take the idle screw out or should i leave it slightly in so the throttle closes on that? wont damage the throttle by letting it snap shut like this?

Yea the TPS is within spec for everything else.

Thanks man +rep 4 u

[rob]

Im really glad i chose to go this morning....

Dyno chart here:


Anyone guess whats wrong here? Its so piss lean its not funny. Basically once it starts making boost it leans out and keeps heading leaner. Starts around 14:1 he stopped when it was heading towards 17.5:1

Its very scary that the car would of been like that for the last 100,000k and ive done heaps of thrashing etc in that time too

I bought a walbro on the spot and will put it in this arvo or tommorrow.

I believe this will be the cause of my hesitation and 1/4 -> full throttle feeling.

Just angry at myself i didnt get the car dynoed earlier!

what a n00b, sif you would build your car like that and then thrash it for 2years, your mate sounds like a champion tho, he must give you brown pants when he drives it, and have good intercooler pipecrushing skillz, not to mention proficient in tuning discometres and obviously dead sexy.

[CrUZida]

Im going to just take the idle screw out or should i leave it slightly in so the throttle closes on that? wont damage the throttle by letting it snap shut like this?

Leave the screw in, you'll need it if the TPS or ISCV stuffs up and you need a temp fix to stop the stalling.

The dashpot will stop the throttle from snapping shut.