1jz-gte major power taper beyond 5000rpm

[urantia]

Just read that bit too chris, and am reading the rest of that thread, good read! -

So if my base timing is out, how do you adjust it on the 1jz? the 7mgte had a cam position sensor you would loosen the bolts off and turn to adjust timing pretty much like a dizzy, but for the 1jz i'm not sure. (would probably be in the 2jz-gte engine manual which is floating around the net somewhere)

[chris davey]

1jz CAS doesn't adjust. Basically, if your cam gears line up at TDC then the timing should be spot on. I don't know what the stock ecu does for timing at idle but when I syncronised my microtech it was at 10. When it idles it is at 15 which brings the revs up a bit.

[urantia]

Ah ok i didn't know this, set and forget timing i like that. I'm %99 perfect sure my timing is spot on in that case but i will check to make sure so i can cross it off the list.

Not much left to try but i will get a video up for you guys to see what you think.

[urantia]

welp i had the battery disconnected over night reconnected in the morning to work. And it seemed better. But i didn't get a real good stretch of road to test it with traffic but it felt more torquey.

Also this is something i've been meaning to ask. How to charcoal fuel canisters work? does the vacuum from the throttle body constantly suck air thru these charcoal canisters? becuase mine makes a strange noise. And when i pinch the vacuum hose going to the charcoal canister my boost guage nearly doubles is its vacuum reading. (from minus 10 to minus 20 psi or whatever measurement it is in. will confirm,

But yes i was always suspicious about this charcoal canister and the racket it was making. ( i tired another charcoal canister from my 7m but it also made the same racket. It's as if i had a vacuum hose not connnected to anything and just sucking in air. (or blowing air out under boost)

Maybe it needs a 1 way valve or something? not sure a tiny vacuum hose could cuase my problems or not.

[SL666]

It should already have a one-way on it..(in the canister) eg, the engine should be able to pull air through it, but not push boost into it, and it usually won't do it all the time... won't hurt to disconnect the line, plug it and take it for a spin.

it does seem odd that it would be using so much vac..


how much vac does it read? cold and hot?

[urantia]

It should already have a one-way on it..(in the canister) eg, the engine should be able to pull air through it, but not push boost into it, and it usually won't do it all the time... won't hurt to disconnect the line, plug it and take it for a spin.

it does seem odd that it would be using so much vac..


how much vac does it read? cold and hot?

Ok interesting! well my canister seems to be going all the time. I don't believe the canister is at fualt becuase i tried another one with the same result. (always going, and always making a racket)

The vacuum readings seem to stay the same cold or hot. My boost gauge has zero where the needle sits when the car is off, when i turn the car on the needle goes to minus 10 (psi?) when i floor it the needle goes +10 PSI

And when i block the vac hose to the charcoal canister the vacuum goes to minus 20, idle comes down quite abit actually. Seems like a hecek of a lot for a small vacc hose to cuase.

Wonder what is up? so the this charcoal canister also hs a line that goes to the fuel tank for fuel vapours to escape from? I must have an air leak in that pipe perhaps?

[SL666]

hmm thats pretty strange.. does your fuel tank have a sealing cap?

i'd say thats probably not helping your situation, but as i said, it should have a check valve on it so you can't pressurise the fuel tank.

[urantia]

I thought my old cap might of been leaking so i got a new one just incase but no change.
So by blocking the vac hose to the fuel canister normally it shouldn't increase the vacuum in the thottle body and lower the idle?

[wiso]

not really sure, never had my 1j running, but most engines (well others i have had, 4a,3s etc) usually idle at about 20inHg or whatever it is, so -20 on the guage

charcol canisters usually do constantly make a sound i thought, usually always crackling

[urantia]

Interesting! yep inHg is the measurement my boost guage has in the minus range.

Sounds like when i block the vac to the canister and my vacuum shoots down to -20inHG, thats its now in the normal range where it should be.

Test for tonight is reset ECU, block off that vac hose and take it for a spin. Will report back results.

[Endless]

My 1jz is at -20inHG on idle, sounds like you might be onto your problem.

[urantia]

AH HA! thanx for confirming that Endless!

This actually explains a few things such as why my idle is 2000rpm on first startup.

Now if only i could find out the official toyota way of how these charcoal canisters are hooked up. Looking at the 7mgte setup they are connected with a BVSV sensor. i just copied what my 1jz halfcut had which was the charcoal canister directly connected to the intake plenum via a vacuum hose, incidentally i have my heater VSV and turbo pressure sender unit running off that same vac hose with a t join. (and now i also have my boost guage plumbed in there too.)

[wiso]

mine is hooked up a little differant than that

behind the diagnosis box is a vac nipple, mine is hooked out of that, it goes to a t peice under hte manifold.

the other one out of the manifold that has the turbo sensor and heater unit are tee'd off between these 2 only

[urantia]

Ah ok that is different to mine. reckon it would be a pain in the ass to get a photo of your setup?

[wiso]

np man, this is how mine is