1JZ VVTI no boost.

[Nat]

I have a 1JZ VVTI out of a 10/96 JZX100 Chaser not making boost in a ½ cut just getting it ready for a conversion. I am working though it just thought id post up to see if anyone has any different thoughts

The boost gauge sits in vacuum at about -.7bar raises on idle to about -.4bar with higher revving and drops back down to around -.5-6 bar even with the revs kept up.

I have read though as man threads I could find, I ½ expected to find a heap of the rear wheel missing or something

I tried the following, well this is what I can remember I was at it all day. Nothing had any effect. Single turbo remember VVTi 1JZ

- Different Boost gauge.
- Pulled off piping at outlet and there was a fair bit of air coming out but I’ve never felt it before so I don’t know if it was enough.
- Put a pod filter on it would have expected it to make a fair bit of induction noise there was next to none.
- Searched all Vac hoses and IC piping for cracks leaks ect.
- Bypassed the whole Factory IC piping system with piping stainless piping I had around.
- Blocking off the Factory BOV port
- Blocking off actuator Vac piping and keeping it wired closed.
- Unplugging vacuum switch just behind the BOV
- Should the ports on the front housing see boost on the gauge? Because I assumed they should it just read at 0 bar thought it may see vacuum like the rest of the system but wasn’t sure.

- I have begun to pull the turbo off but run out of time this afternoon. I have another turbo which appears in good condition to replace it.
There is a fair bit of oily residue though out the IC piping.
There is about 3mm of shaft play back and forward on the turbo, the one I have to replace it has virtually none. The impellers in the turbo all appear intact.

NaT

[Pube]

I think its difficult to make much boost or boost at all without the engine loaded up ie. in gear with a diff and some wheels back there! Are you just simply revving the engine in the half cut in neutral?

[Nat]

Thanks for that, Yeah its in netural i thought that may have been the case. I've always had NA cars so im a bit new to it all.
I was wanting to replace the turbo with the one i had anyway it was a bit smokey.

[oldcorollas]

yup, no load = nearly no boost....

[Smokey228]

I can get my car to make 1 or 2 psi riding the shit outa the clutch! But in neutral your going to make close to none man!

If there is 3mm shaft play and your other turbo has next to none, i'd finish swapping them off anyway!

Try putting it in gear, heavy on the brakes and then throttle it, it might make 1 or 2 psi, or it might bog down and make nothing at all!

Cheers<
Jase

[Nat]

Thanks boys, new turbo is in, least i have a better idea of the condition of the turbo its running now.

[JP]

FWIW my vvti 1J can make 3-4psi free reving, just hard stabs of the throttle.

[Nilezy]

Yep I agree with JP, I get 1-3 psi free revving.

That turbo is stuffed with that much play. The turbo has a design flaw which causes them to become stuffed above 80,000 kms.

You might want to check that your engine is not in limp home mode, like mine was when I first started it, allowing me to see 11 psi at WOT, but the VVTi actuator was on full retard, so the engine was making no power.

Cheers,
Nilezy

[Nat]

Well its sill behaving the same with the other turbo. I was just trying to get it all sorted before transplanting it. Ill have anther look when i get a chance.

[mr2gze]

That turbo is stuffed with that much play. The turbo has a design flaw which causes them to become stuffed above 80,000 kms.

Cheers,
Nilezy

Slightly off topic here, but I think that is a huge call. I have driven a jzx100 a few times on 13psi with +160k kms. That has seen 13psi for most of its life (ie. 70k-160k kms), with no turbo related issues present. It go's the same as it did @ 70k kms. Furthermore Ive seen and driven numerous x100's with > 80k kms.

Yes I know this is just one first hand example. However it more or less disproves that the turbo has a "design flaw which causes them to become stuffed above 80,000 kms." If its something you have observed over a few examples. . . fair enough, however there are a myriad of reasons why a turbo can fail, I wouldnt be so quick to say it has a design flaw.

cheers

[Nilezy]

Hey,

On all the JZX100 turbo's I've seen pulled down, they all show signs of the steel plate pressed into the back of the thrust washer coming undone, causing the plate to press against the bearing that runs against the thrust washer, wearing it out so the shaft moves, and rear oil seal, wearing it out to the point that the turbo burns oil in the exhaust, either excessively like my engine, or slowly building to a point that they will blow blue smoke. The turbo will still run, create boost, and not make a sound, except blow a little or alot of blue smoke. In my case, alot of blue smoke, hence why my engine was not in a front cut, and cheap.

Yes it is my opinion that the turbo on a JZX100 has a design flaw. The plate is pressed in with 4 or 5 really small tabs, that are easy to break under normal engine vibration, causing the plate to fall off. Your'e right too in that you can buy a JZX100 push it hard, and the plate may not come off and cause the oil seal to wear out, but in most of the cases i've seen, when it comes off, you'll know it has. Most of the imports are under 80,000 kms so it's also an observation from that they would do it over 80,000 kms, as my engine has done just over 100,000 kms. Hey, don't let my opinion stop you from buyin a JZX100!!! They are a great car!!! The turbo's are not impossible to find to replace if you have one that has free play. If I was buying a front cut with unknown k's, id pull the front piping off the turbo and check the free play, as well as checking if it blows any smoke when running.

Curious to find out if Nat has pulled the turbo down, and if the plate has come undone, to just float on the shaft against the thrust washer bearingl??

Cheers

[jure]

mines fine (no blue smoke) and its done 140,000kms... runs around 12-13 psi

[Nat]

The cars been running for a couple of weeks now, is boosting fine to 10.6 PSI so yeah it was the fact that it was just in the cut free revving, its running 3 inch dump pipe, greddy PEII exhaust but still running a restrictive mid/Cat pipe, HDI GT spec Intercooler kit and pod filter, stock Auto ECU wired to run a manual, for the time being. Have a boost controller but haven't wired it in yet.

No smoke with the better turbo installed.