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Lambda sensors


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Quote: from HedgehogSandwich adi on 10:32 pm on Mar. 26, 2002[br]

Right....next point. I distinctly remember the lambda on my old mk3, size shape etc. I've had a look at my JZA and it appears there is one under the turbo's somewhere, possibly near the downpipe...but like i say very near the turbo's. There may be another but i haven't spotted it yet.

 

There would only be a second one if it's destined for California :)  Rather strict emissions laws...

 

So it seems you still have the thing installed - that's a relief.  The missing at high revs you mention may be you needing a colder grade of spark plugs as the boost is higher than stock.

 

I think Ian is right that the lambda is in the downpipe.

 

Whoa - we just ascertained that it's *not* in the downpipe!  It's "term definition time!"

 

There are three sections to the exhaust:

*The back box - sits at the back, has huge outlet on it to show off your manliness :)

*The centre section - sits under the length of the car, connects to the back box and the downpipe.  Occasionally catches on speed bumps/kerbs/etc.

*The downpipe - attaches to the centre section and the turbo exhaust outlet pipe.  Has a CAT in it, and the temperature probe.

 

The turbos have an exhaust outlet pipe, which takes the exhaust from the turbos, joins them to one stream, and connects to the downpipe in a clean fashion.  This is the bit that has the lambda sensor on the MkIII and MkIV Supra  It's not the downpipe.

 

There is a flange where the turbo exhaust outlet pipe is bolted to the downpipe.  That's the demarcation between pipes.  So which side of this flange was the lambda sensor?

 

The 1JZ soarer and 1JZ supra are seem to share block and head, but thats about it. As far as inlet, ECU's, exhaust, and various other bits they are different. So, you can seem my dilemma. At the moment Mycroft and the lexusclub are my best source for info, yet after that its guesswork.

adi

 

That would be me classed as guesswork, then - cheers!  :biggrin:

 

One last question - where did you get the downpipe from?  Was it a custom job or a tuning shop part?

 

-Ian

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Right, clarification time. Yes in the mk3 3.0, the lambda is in the downpipe, and the cat is in the centre section (i still have my old 3.0 exhaust in the shed). The cat is also in the centre section of the JZA70, away from the downpipe. Therefore the lambda is in the downpipe, but not in the cat, nowhere near it. It MAY sit in the turbo elbow, it certainly appears to, yet i would have thought this is unlikely.

 

So, we go turbos, turbo elbow, downpipe with lambda, centre pipe with cat and heat senosr, back pipe.

 

So no i haven't got a new downpipe, i have a replacement pipe the same size as the cat, about 12 inches long straight section.

 

 

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Guest Martin F
Quote: from HedgehogSandwich adi on 11:07 pm on Mar. 26, 2002[br]Right, clarification time. Yes in the mk3 3.0, the lambda is in the downpipe,

 

No it is in the turbo outlet elbow.

 

Open the bonnet and it is staring you in the face!!!!!!!!!!!!!

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I'm completely effing confused now!

 

Turbo outlet elbow - that's the proper name, I couldn't remember it.  That's where the sensor is on the MkIII and MkIV.

 

The back box ends roughly where the back axle is.  The downpipe ends roughly where the footwell starts.  Does that clarify what the centre section is?

 

-Ian

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Guest Martin F
Quote: from Ian C on 11:17 pm on Mar. 26, 2002[br]

 

The back box ends roughly where the back axle is.  The downpipe ends roughly where the footwell starts.  Does that clarify what the centre section is?

 

-Ian

 

By process of elimination....... :biggrin:

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Were actually all on about the same thing. It just got confused. Yes the lambda is in the turbo elbow of the mkiii 3.0t, my mk3 2.5tt, and as you say the mkiv.

 

My cat is in the centre pipe, smack bang in the centre of the car, with a heat sensor. The soarer cat is also in the centre section, yet with a lambda sensor instead of a heat sensor.

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Guest Mycroft

It's like watching the bewildered leading the blind, you should all go on the stage, people pay good money for this sort of thing.

 

You ARE funny.

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Quote: from Mycroft on 12:05 am on Mar. 27, 2002[br]It's like watching the bewildered leading the blind, you should all go on the stage, people pay good money for this sort of thing.

 

You ARE funny.

 

Mycroft, do not patronise people on this BBS. If they are incorrect then please correct them, or if you dont know the answer then say so and perhaps Chris will explain everything we need to know.

 

JB

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Mycroft, do not patronise people on this BBS. If they are incorrect then please correct them, or if you dont know the answer then say so and perhaps Chris will explain everything we need to know.

 

JB

 

I am flattered, but have the humility to admit I don't know everything, although I have to say I DO know how an O2 sensor works in conjunction with the ecu. Those after a well presented if fairly simplistic answer would perhaps care to look at the following web page and links therefrom, it answers many of the questions people may have in a far more lucidly presented way than I could hope to achieve.

 

http://www.howstuffworks.com/question257.htm

 

I hope this BBS isn't going to degenerate into another mini skirmish....

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Guest Mycroft

Did that come over as patronising?

 

I certainly wouldn't what anyone to get that impression, but you have to admit that confusion seemed to reign for a while!

 

A little light relief, I thought.

 

 

Edit;

Chris, good website, perhaps a permanent place for it here can be found, would stop the merry-go-round of confusion!

 

Have pasted it to the LSOC already.

 

(Edited by Mycroft at 12:51 am on Mar. 27, 2002)

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Guest Martin F
Quote: from Mycroft on 12:05 am on Mar. 27, 2002[br]It's like watching the bewildered leading the blind, you should all go on the stage, people pay good money for this sort of thing.

 

You ARE funny.

 

Well that really added to the technical debate!

 

 

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It's like trying to play chess with a fly buzzing around your head...

 

Look, until I get a first hand view of a soarer or a 1JZ equipped Supra, I can't really add much more.  I'm not about to pretend I know more than I do about soarer lambda sensors etc..

 

I'm getting the impression that us all clubbing together and trying to learn stuff is amusing to those closer to God than I.  That is, however, what this BBS is about.  It's not always going to be clear, and it's never always going to be correct, but it's more useful than doing nothing, and I'm not about to stop it due to heckling.

 

Mycroft, if you want to help, why not post a photo or even the technical manual schematic of the 1JZ exhaust system - clear it all up once and for all?  I can't see why you haven't done this already, you must have these sorts of resources available.

 

-Ian

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Guest Martin F

 

Yes we may have gone around in circles for a while,  but i think i'd be right in saying it was an educational experience. Exactly what this part of the BBS should be about.

 

However it does seem to be suffering from a low signal to noise ratio recently!

 

 

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Quote:

Mycroft, if you want to help, why not post a photo or even the technical manual schematic of the 1JZ exhaust system - clear it all up once and for all?  I can't see why you haven't done this already, you must have these sorts of resources available.

 

-Ian

 

This is the whole point, and where the confusion arose, the 2.5 soarer and the 2.5 supra are completely different outside of block and head so mycroft posting a pic of his soarer still wouldnt have cleared the problem up.

 

Glad we got there in the end.

 

Cheers

adi

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Quote: from HedgehogSandwich adi on 11:52 am on Mar. 27, 2002[br]

This is the whole point, and where the confusion arose, the 2.5 soarer and the 2.5 supra are completely different outside of block and head so mycroft posting a pic of his soarer still wouldnt have cleared the problem up.

 

Glad we got there in the end.

 

Cheers

adi

 

I guess the confusion started, then, with soarer-specific information being posted with regards to a Supra based problem.  That explains things.

 

-Ian

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Guest Martin F
Quote: from HedgehogSandwich adi on 11:54 am on Mar. 27, 2002[br]Low signal to noise ratio? you a sound man? I worked in live sound for years, really miss it now...

 

Anyway, off topic...back to technical stuff.

 

adi

 

Nope RF\Telecomms

 

 

(Edited by Martin F at 2:25 pm on Mar. 27, 2002)

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The 1JZGTE engine is the predecessor to the 2JZGTE, and the whole mkiv supra engine is based on the 1JZ. The technologies are the same, coil top plugs, same style block and head, similar fuelling , elctrics etc, so they are very similar generically. They share many ideas, with the 1JZ being thought of as a prototype for the 2JZ (and in certain ways is more powerful :)  )

 

I also have had nearly all makes of supra since they started doing them in 1979, and consider myself to be a future mkiv owner. So i reckon i can get away with posting on here.

 

Like i said in an earlier post,  the info on the 1JZ is very hard to come by, as a result i have to take bits of info off here, the lexus site, and also off the UK supras site, which have been very helpful over the past couple of years.

 

adi

 

 

 

(Edited by HedgehogSandwich adi at 3:26 pm on Mar. 27, 2002)

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