We did a couple on last Sunday, mine & DataBitz's.

Bodin came around in his 1GFE but it was quite different and I coundn't see the MAF sensor on it. Any ideas there??

We did find his rear tyre scrape problem tho'... No scraping on the side with negative 2.5deg camber and plenty of scraping on the side with zero camber!!

Wheel alignment coming up! :D

Here is the 10mm bolt you take out at the start-




...and here is the MAF sensor itself.



Held in by two very tight Phillips screws, so push on the screwdriver hard and turn slowly to loosen them.


This is the unit. There are two areas to clean-

1)- The two metal arms here, probably a bi-metallic probe.

2)- Down inside here are two resistors. The air goes down this hole, around the end and up the back of the arm into a negative pressure area. The resistors cleaned up nicely with a couple of squirts of CRC brakeclean.

(You could use Nulon Brakeclean, they are both based on chlorinated hydrocarbons- ie drycleaning fluid, but other brands may also have oxygenated hydrocarbons like ketones or ethers, which may not be good for plastics. The chlorinated ones are propelled by carbon dioxide, the oxygenated ones are propelled by hydrocarbons, usually butane. The chlorinated ones are usually heavier, over 400gms, as chlorine is heavy and they only need 5gm of CO2 as propellent. The hyrdocarbon propellent in the others takes up about 1/3 of the can and they are lighter.)





If the dirt on this arm is quite tough you can use a strip of rag with brakeclean on like this. The cotton bud is too big to get in there.



Nothing can go down the tube to the two resistors tho'

Does it make a difference??

Don't know, I won't be using Greeneyes until the next trip to Rotorua in the middle of December! :lol:

Aha! This from our cousins in the UK-

http://www.lexusownersclub.co.uk/forum/ind...showtopic=24149

omg your a bloody ledgend!!! shot man for the step by step guide...but is there anything else i can use part from brakeclean that might be found around the house??? or best to stick to that???

thanks again man...

i wouldn't use a cloth to clean it.

infact i think your very very brave for doing so.

use an eletronic cleaning solvent, spray it on and it literally wash's away the dirt and drys in seconds.

the tip of the MAF is platinum coated iirc... so u don't want to be proding and poking it!!!!!!!!!!

What's iirc Mr S??

The sensor I cleaned with the cloth is the ambient air sensor. It is two legs of metal about 2mm wide by 0.75mm thick, and the bulb at the top was resin. The legs were quite sturdy. In the photo it is still dirty so the clear brown colour of the resin doesn't show up.

The resistors down the tube for the MAF were literally just resistors off a circuit board. I put nothing down there!

I don't think there will be anything around the house that will clean them. Most household cleaners are water based, and you wouldn't want to try meths. Use brakeclean or electronic contact cleaners.

Don't use carburettor cleaners (too many ketones in it) or engine cleaner (detergents plus white spirits or kero!)

keith (ex-CRC Chemicals Chemist!)

IIRC - if I recall correctly. Here's more from a similar genera.

I concur with your thoughts on the ambient air sensor, it does appear quite sturdy. I'm also not going to disagree with your view on the chemicals in the various cleaning products - my chemistry is limited to only 3 or 4 papers at uni. :)

As far as the thermistors are concerned Platinum is a possibility. It's commonly used in thermistors as it's a nicely heat sensitive element. It would have to be exposed to the air, so it wouldn't be protected by a resin like the ambient thermocouple. As Mr Singh suggests, you probably would want to be very careful how you handled them...

And just so we don't loose track of them I'll reference some of the other posts on MAFs so that we can consolidate into one FAQ at a later date...
http://forum.altezzaclub.org.au/index.php?showtopic=2026
http://forum.altezzaclub.org.au/index.php?showtopic=2032

Thats very impressive, who needs turbo !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :o

Tezza has done 117000 kms and its like new again. :wacko:
Nice idle no bubbles.
Excellent acceleration and (auto) gear change very smooth.

I've used CRC Precision Contact Cleaner proably took about 10 minutes.

I also recorded KPL at 9.86 prior to clean and noted that the inside of the
exhaust pipe is very black. :boink:

wow bro... the info is valuable to me man..

Mine is slighting different. Cos my engine is a 6 cyc not the RS model engine.. (Cant recall wats my engine code name 3G??) haha..

If thats the case i think i should be able to find the MAF.. Will try out this weekend if i can have my hands on cos i have burnt my last weekend working through the nite :(

I will take a snap shot of mine if possible and post it here.. Cheers.

Everyone who hasnt done this yet... DO IT NOW - cleaning the sensor made the car feel so much better and probably more powerful than after installing my muffler... i have an apexi intake also...

Good luck with finding that. The 1G-FE uses a MAP (Manifold Air Pressure) sensor.

Apparently it's hidden somewhere between firewall and airbox. I don't know my way around the engine bay of IS200s...

Bro, now then i remember that i have the original parts manual with me which i bought from my fellow forumer.. Will check on the manual for it and see where the hell this MAF is hidding.. :D

If possible i will scan it and post it here too.

I checked over Bodin's (Kiddo) 6-cyl and there is no equivalent sensor. There is a plastic sensor in the air filter box that has no wires showing at the end of it at all, I think its probably a temperature sensor.

So check the manual TRD- I don't think you will find a MAF sensor on the six-cylinder 1GFE

thks bro.. Will check it out.. hopefully the parts manual has the picture shown.. Cant remember where did i hide the manual at home.. shucks!

Isn't that what I said above? IT USES A MAP SENSOR, not a MAF. And the MAP sensor is downstream of the throttlebody somewhere...

Hmmm... You wouldn't like to scan the odd page or twohundred of the manual and post them up as PDF files??? We can host them with T'bird in Aussie and download as we need them.

If it's not too big I can do it at my place, or DataBitz can also.

I've never seen a manual for these cars.

nah.. wont be converting the 2 book repair manual into PDF.. each book is about 2 inches thick..

The book title is "LEXUS Repair Manual IS200 GXE10 series, Jan 1999. Pub no RM684E2"

scrolling thru the think manual now.. cant find the blardy sensor except for Throttle position sensor under Throttle body.. and air intake temperature sensor components.. man..

LOL! I thought it might be like that!

So, does it make a difference?? Well, I went down to Huntly & back today at a nice 120 on the speedo and it revved nice and cleanly...

mind you, the BP station I filled up at had dropped 96 octane and only had 91 or 98. This is the new policy apparently, some will have 91 & 98, the others 91 & 96. So maybe the higher octane helped!

It seemed to idle slightly lower (right on 750rpm) and had the occasional light hiccup at idle. But the trick is... don't spend time idling! :lol:

Still, a bloody marvellous car to drive in the countryside!!!

Fuel Useage

Before MAF clean 9.86 KPL
After Clean 10.08 KPL

So if the standard deviation on your fuel usage is anything like mine those results show that there is no statistically significant difference between before and after.

See the variation from fill to fill in this thread. You need several months of data before you can say with any sort of confidence that there is a difference. :)

You're proably rite, just showing figs as they sit.

Cheers

Clean MAF sensor

:rolleyes: :lol:

You cleaned the temp probe, not the MAF. The MAF hot wire anemometers are tucked away inside the black tube - do not go near them with any solid object, they're very fragile.

I use this. works like a charm


I cleaned it about 2 months ago and have since travelled 5000kms. It was filthy again so I cleaned it again this weekend past. Much Better !

Most people actually use this:

So you use this to clean both the maf sensor and the temp probe?

Is it just a matter of spraying it on and leaving in for a bit? Is there any need to still clean the temp prob withna rag?

Sorry, bit of a nub here... and don't wanna cause any damage :unsure:

Yeah thats all I did, spray it and left it to Air-Dry, we could look at doing a few cleans at the meet if someone already has a bottle of contact cleaner :P .

Hi Andyc

Don't use the rag just let the unit air dry.

That would be wicked :D I'm happy to buy and bring the cleaner.

The drive from Wenderholm back to Auckland would be a nice drive to test the results

I have noticed that all the plumbing from the intake to the intake manifold has a bit of greasy black build-up. Will cleaning this out with brakeclean and a bit of a wipe help the cause also?

It will clean out fine, but it shouldn't make any difference!

I found this product CRC Mass Air Flow Sensor Cleaner on the shelf at Repco. It is developed specifically for MAF sensor cleaning.
I used it and it worked a treat. No need to worry about damaging the wires as you only spray them and don't go near them with a rag. It is safe to use on plastics and on the O-Ring that seals the MAF sensor in place, you can also clean up the black muck in the intake area.

Other products like Brakleen can be to harsh on the components with the potential to cause other problems.

This link will take you to the CRC product info page for their Mass Air Flow Sensor Cleaner product http://www.crcindustries.com/auto/content/...px?S=Y&PN=05110

This link will open a technical brief pdf file by CRC on how to use their product to clean you MAF sensor http://www.crcindustries.com/files/19965_1.PDF

Both worthwile looking at before you use Brakleen or other product

It cost $20-99 at Repco (cheaper then replacing a damaged MAF sensor)

LOL!

Knowing CRC it will be Brakleen in a different can!!

Yeah that's the stuff I used

Gone and made me cry now ;( worst timing for this thread to be brought back up imo.

I think you are right Keith...I got a can of the MAF sensor cleaner about a year ago and the smell was no different to the brake cleaner I had at home. and its almost twice the price from what I remember

A note for users of this stuff is to remove the Oring from the sensor first...I didnt think to and it expanded the Oring enough that it wouldnt go back in the hole

Aaron y'ol hoon! long time no see!

Yes, seeing we are only cleaning off oil almost anything will do it.

Petrol would be fine, just don't set fire to it!

But that's good advice about the O-ring, and don't soak the unit in anything for any length of time as a lot of modern solvents dissolve plastic slowly. A quick blast with an aerosol should do it.

I tryed to get the MAF sensor out but the bottom screw is too tight and starting to strip am contemplating taking the whole air box out to clean it
Any ideas on how i could loosen this screw?

You could try a pair of side cutters, gripping between the inside of the screwdriver slot and the outside of the screw (hope that makes sense) then turn the cutters to release the screw.

Let us know how it goes.

Where in Chch are you Hypno? I could swing by after work if you need a hand. I live in Leeston, but work in Hornby

anyone on the shore have a can of the AFM cleaning stuff I could pursuade the use of? lol... ill be really nice to it :lol: