Dawes AFR strangeness... *confused*
 

ok,
had a Dawes AFR fitted (TSL) and the unit is constantly on BLUE (ie: mega rich) on WOT..

'destructions' quote that : "Blue light stays on all the time: You have the white wire connected to 12v. You may have connected to the 12v line for the oxygen sensor's heater" BUT the technician (bye Ian!) double checked the wiring and its all FINE...

bear in mind my car:

550 injectors,
hybrid turbo
FMIC
LINK ECU
uprated fuelling (components and pressure)

??? SO is it just that the MAP is too rich? Pat mapped it using wideband and got it damn near spot on stoich mostly..
??

knackered lambda perhaps? btw- the AFR is soldered onto the lambda as close to the sensor as possibe..

any ideas guys?

The fact that the blue light is on from what you've said is normal, if the blue light is on when the engines not running but the ignition's on then you have a problem, you should be getting blue on WOT, thats the whole idea!!
The lambda's not knackered, is working fine, if it was knackered the afr would show nothing!

The car should run rich on WOT - the extra fuel helps prevent detonation and cools the cylinders too.

Rich

It should flash back and forward at idle / cruise. Blue on WOT.

Anything else, you have a problem.

Trouble is with the dawes, is there's only 4 lights so you cant get an accurate voltage. Having said that, as long as its blue, its fine, and non of them are very accurate. More of a guide.

MB

it IS accurate to 0.05v though according to the technical docs from DawesDevices..

the blue light is on all time at idle/WOT

according to their instructions I *should* be running on the yellow light @ WOT.. (yellow- near as stoich as dammit) when my map was done it was with Wideband and the fuelling was setup only for being overly rich on cold starts..

bit bemused? altho to their credit TSL have offered to check it all again to make sure, and I have emailed JWR to let him know..

*sigh*

feckin cars..

It may be accurate within itself, but if it doesnt have about 20 lights on it, so how do you know where in the "Blue" light you actually are? It probably has a range of 0.75-1v or something. Even so, its good enough for what we need :)

MB

Chrome,
was it on at idle when the engine was cold, or hot, as when cold the engine would be running rich, as if it were on choke, that might go a little way to explaining it!

on whenever... when it was fitted the car was cold.

I drove it home some way, and drove around a bit more.
got home. turned it off. then went straight back out (hot start)

the blue light was still on, and stayed on :(

Ah, its on all the time. That means you either have a 12v signal going into the gauge, or the sensor is buggered, and has failed full scale +ve.

You haven't changed the sensor lately have you? If you get the wrong type, this can happen.

Best thing you can do is get a volt meter onto the signal wire, and see what voltage you're getting.

MB

Hey DBM, guess where i've seen this before? Remember our "conversation" earlier this week?

hi this chap knows his stuff

ok. cheers mark.
probably a buggered sensor :rolleyes:
TSL were certain the wiring was spot on..

Mark, it does look similar :)

Stephen, ta (if you meant me :D) I know a little to help out here and there.

Chrome, I have just read that BRD sell "cheaper" but good sensors. Well worth getting a new one and see what happens. I would trust TSL's wiring, so supect the sensor. Although a bit odd it was ok when recently mapped, and now its not :confused: They can just die though. Given your mods, its probably a bit hotter than normal ;)

If the new one doesn't work, at least you have a spare for when it does die! Keep us posted, its good to see these things resolved.

MB

good advice. will ring bob/branko and see whats what :)

will keep you all posted..

Hi Brad

YHM

It could be one of two problems, the knackered sensor or the fact the feed was taken directly off the sensor and not off the ECU.

As I said in the email though, we have never had a Dawes AFR go wrong so please don't worry about that.

Let me know how it goes.

Jamie

www.dawesdevices.co.uk
www.j-w-racing.co.uk

ECU and lambda feed are the same :confused: From the sensor it goes into the loom, then to the ECU.

My bet is still the sensor.

MB

Mark- That was my immediate thought.. soldered to the lamdba sensor wire as close as poss for an uninteruppted (sp) signal.. as per the Dawes instructions... but no joy. Blue all the time.. no matter what the scenario.
ign ON- Blue light.

Now waiting to hear from mr dawes himself via Jamie, and TSL only did as instructed via the fitting notes- http://www.dawesdevices.com/wrxmeter.html

I'm not happy particularly as it should have been so straightforward... now I have to take yet more time off and spend more cash to fix it... grrr

hoping this can be sorted swiftly..

:(

Just out of interest, how did you solder it onto the sensor? The sensor wire is made of a funny material, that would not solder when I tried a while ago. Im sure you have a proper contact, just interested.

Still pretty sure its not the Dawes itself.

You still need to check the voltage at the signal wire, as it may just be stuck at 1v and the sensor has failed rich. Get a test meter on there.

MB

Just had it confirmed this morning that the new lambda sensor that was fitted is faulty. A new one will be fitted Friday.

Result ;) Thought as much.

MB

HOW MUCH IS A NEW LAMDA SENSOR?

Depends which you buy;). Mine was £50. They can be got cheaper though.

Mark- lemme know where you got yours please ;)

PM or mail ... ta :D

I have a Dawes AFR, so because it hasn't got about 20 lights on it it's not accurate.:rolleyes:

yeh where from dude?

In my opinion, the 20 light gauge is more useful than accurate, as it shows you all lambda activity, rather than just in the stoich/rich area, which can help to diagnose problems. For instance, if there are no lights after wiring up your Dawes, how do you know the gauge is seeing any signal at all? A 20 light gauge would indicate some voltage, however small. It could help point you in the right direction...

Chrome,

For reference once the new sensor is in..

At idle it may well be blue etc as with mine you have 550 injectors and a Link and mine wanted rich to idle.. but with ignition on but engine off it should be no lights.

On boost and foot to the floor you should see blue light..

The Link ECU is not using the Lambda, you are just using the dawes as a monitor..

I too have a Dawes AFR etc..

Simon :)

Lueven,

Calm down. None of them are totally accurate, and you dont need them to be. They are only useful as a guide. I just prefer the autometer, as Judge says, it gives you more info. Less lights clearly gives you less info, but depends what youre after.

MB

They're all as accurate as the lambda sensor they're connected to... :)

cheers JGM :)
Im using the OE ECU currently with lowered fuel pressure as my LINK is poorly :(