Thought i'd start this before they all arive from Jamie's group buy.

I believe that the online instructions are to connect to the lamda sensor? Is it better to connect to the ecu? Comments please.

Thanks

Paul

ECU better IMHO because easier, no need to cross firewall, no chance of corroding wires in the offensive environment of the engine bay - our 406 recently broke down because of this issue.

Paul

see

http://www.scoobynet.co.uk/bbs/thread.asp?threadid=73872


Martin

cheers for that guys.

http://www.ravensblade-impreza.com/index1.html

afr in interior shows connection to my99 ecu

quick question, sorry for being lazy and probably dumb ;)

I take it that the white wire from the dawes afr goes to the ecu red to live and black to earth yes?

Cheers

Paul

RTFM ;)

Dunno. I wouldn't presume anything.

I'd be a bit more helpful if I understood your last statement!

It needs (presumably) 12V 0V and signal. if there is a red it is likely to be 12V, black 0V, white signal, but PLEASE check the instructions. I took ground from the sensor ground at the ECU. 12V from the stereo - if I blow that 12V at least I know the culprit - my dodgy ICE install or the AFR.

If you take any old 12V and the fuse goes you might be immobilised.

[Edited by john banks - 3/5/2002 1:54:00 PM]

John

I take it that I am alright to just take the power and earth from the cigaret lighter. The Instructions show white to lamda so presumably this can just go to ecu.

Cheers

Paul

Sounds fine.

Potentially you could have an offset if you ground distant from the sensor, but there was not one on my car, but I just picked up the ground and lambda signal at the ECU.

hmm, might be a stupid question but which wire from the ecu is ground? Is there lots of them? Remeber I havent looked at it yet so bear with me. I am going to place the sensor in the actual spare switch near the cigaret lighter by driling holes for the lights so my closest earth is there.

Dawes Instruction says that ground wire must be attached to negative of battery to ensure correct readings from the AFR.

Thats gonna be messy! He does say that though you're right. Plus I'll have to extend that wire by quite a bit to get over there!

What is so special about the battery? Surely the signal ground is better - that is what you are measuring?

On my car I could not find offsets. Ground it where you like. I know the circuit (since I came up with virtually the same design independently) and it is fine - I have grounded mine at the ciggie lighter, the stereo and the ECU and it always reads the same. It is the relative readings on your car that are important before/after- the sensors are not that accurate open loop anyway.

thats what I wanted to hear John. I am gonna to the lighter.

Cheers

Paul

John,

How did you solder to B136, no 18? Am I just as well scotchlocking to it or is that going to cause probs later?
Cheers

Solder it. Scotchlocks really are for bodgers - I already had one fail.

It's a chop job unless you fancy stripping the insulation.

i'll scothlock it now and when i know alls right ill solder it.

Cheers for the guidance, well practically doing it for me ;)

Cheers

Paul.

Right its all connected. The scotlocks make quite a nice strip in the insulation actually to solder onto!

I seem to getting the orange light constantly under WOT, which Mr Dawes says is ideal. However that is only true based on what Darren adjusted the voltages to.

Jamie, can you confirm what the afr voltages were set to by Darren? Last I read in a thread it was:

> Red 810-830 mV
> Yellow 830-850 mV
> Green 850-870 mV
> Blue 870-890 mV

If so is 830-850 ideal under WOT? I seem to remember you getting about 860mv John under WOT?

Cheers

Paul

I get over 890mV on full throttle depending on revs (I wouldn't want it below 870mV). Under 3000RPM it is a bit leaner.

thats a bit scary!

I should at this point say that my mods are decat downpipe, and centre and ppp. Somethings not right then. I am not running anything else. i.e dawes, boost controller etc.

Maybe I should try a different ground? Really need to know what each light is set at. Hopefully Jamie will respond shortly.

P.S. Where/What is the official guide to mixtures including volts and CO and what is lean and what is rich? Apologies if you covered this in the original AFR thread, I had a look but cant find anything.

[Edited by paulwadams_my99 - 3/5/2002 7:17:25 PM]

[Edited by paulwadams_my99 - 3/5/2002 7:23:37 PM]

Er, you have shown the 2.5 litre engine ;)

You need for the signal pin 21 which is third one along on third row from the top on B136 Blue plug in Link manual.

The ground is pin 30 third from the other end 4th row.

I got the recommended AFR from the Link manual's default map for the boost zones I listed and they went along with what folk like generally say.

http://www.ravensblade-impreza.com/m...ring/link5.pdf

Link Manual is also here.

As long as it is a high impedance digital voltmeter - an analog one would burn the sensor out.

Hope this helps a little:

First Light: Red = .75 to .90 LEAN
Second light: Yellow = .90 to .95
Third Light: Green = .95 to 1.0v
Fourth Light: Blue = 1.0v and up RICH

Those are the standard Dawes AFR settings. Was this batch calibrated to the Scooby using the settings I suggested to you and Darren?

Sorry yes, they were but of course Darren dealt with that.

To be honest Ive just got in after a very busy day so I just tried to post something that might help it obviously doesnt, I'll get some more info off Darren as there isn't anything on our sites at the moment because the demand of AFRs has been so high we've had to temporarily suspend orders of them.

and u suggested what exactly John

The AFR calibration supplied for the Impreza is

1st light (red) .81v - .83v
2nd light (yellow) .83v - .85v
3rd light (green) .85v - .87v
4th light (blue) .87v to limit of O2 sensor

Martin

who else has fitted a dawes afr and what results have they found? Have u martin?