AFR metering

Anonymous · February 25, 2007, 10:37

right then chaps (by chaps -read those with wideband s;)

s;) )

have just started to look at installing the aem uego wideband kit, but the hangover is retarding my logic this morning........... s:? :? s:?

I have previously removed one stock o2 sensor and spliced the signal wires etc and used a heatsink to fool the ecu into believing that the oen heater circuit is in use.

I now wish to replace the remaining stock sensor with my wideband.

The AEM kit uses a Bosch LSU4.2v sensor which is a 5 wire sensor

Red
Black
White
Yellow
Grey

Now, can I splice the stock sensor harness into these 5 wires? (preferred) or do i have to use another heat sink etc and then run a narrow band signal wire from the AEM set up?

Having read the AEM instructions it appears that they are written around two options, 1] using the wideband as a stand alone additional sensor, or 2] running a spare narrow band signal wire from the rear of the actual gauge and all the way back to your ecu (but this still leaves you the problem of fooling the ECU in regards to the remaining stock heater circuit etc)

I should add that the instructions give no break down of the what the 5 wires coming from the bosch sensor are ? They only breakdown the wires coming out of the gauge at the other end (red=power, black=chassis ground, White=0-5v output and Blue=serial output)

Any ideas chaps/ (in idiot proof language due to alcohol 'fuzziness' today)

cheers ma dears s:D

s:D

spit · February 25, 2007, 10:53

Quick question before I bore you stupid with drivel Perry.....

Where are your O2s (going to be) placed? Are they still in the stock-style Bank positions - so that you have the ability to feed the ECU with separate Bank data - or are they reading a summed exhaust from all 4 cyls?

Sorry if you've already told us - I'm kinda losing track of your mod-venture s:wink: :wink: s:wink: s:lol: :lol: s:lol:

Anonymous · February 25, 2007, 11:03

the sensor locations on the PE are one bhind the other on the down pipe, hence the usual practice of either removing one fully (using heatsink) or splicing the feed from one to the other. This being because the second sensor doesnt get great readings when directly behind the first)

this is the stsge I'm at, at present. ie only one sensor, two signals spliced and a heat sink

aaronjb · February 25, 2007, 11:31

If I'm understanding your post correctly, Perry, then you're going to have to run the signal from the WB O2 to the guage first, then take the NB feed back to the ECU, as I don't think the ECU will know what the crap to do with a WB signal.

m http://wbo2.com/cable/lsuconns.htm m

White + Grey appear to be heater elements, so that might well be good enough to be in place of the stock O2 sensor, saving you from adding a pretend-heater element, as long as it has the same impedance when hot as the stock sensor.

But the feed is going to have to come from the guage..

spit · February 25, 2007, 11:33

PE - PErry. I'll remember that now s:wink: :wink: s:wink:

Brace yerself s:wink: :wink: s:wink:

First, what you can't do is directly connect the Bosch signal wire to the signal feed(s) on the stock harness. They have to be fed from somewhere after the WB controller - which will be setup to give the appropriate NB voltage signal (0-1v ish). The WB controller works on a change in current from the bosch, not an analog voltage.

As for signal ground, I used the ECU chassis (cos the Innovate controller is housed in the engine bay), but all of our sensors share plug E4 pin17 of the ECU as a ground so you could use that via the NB socket.

(However, with the Innovate I ran into problems with gauge stability as soon as I tried to use the NB analog on the ECU - something that Innovate put down to conflicting earths - so I reverted to a stock NB O2 feed for the ECU). The analog signal from the WB was great and gave no CELS or running issues, but without an accurate gauge it was a no-brainer to switch back)

As for the heater feed, you could use one of the stock O2 sockets for that - I think the Bosch heater is within the same sort of resistance limits as a stock sensor. But I wouldn't - and this this is where it all falls down......

I don't know the AEM but the Innovate's wiring is very clear. The controller puts the sensor through some tests on startup and allows for heating time as part of the pre-calibration process. It also shows up a series of error codes on the gauge if anything is wrong. If the AEM runs similar diagnostics, I'd be inclined to stick with either option 1 or 2 of AEM's wiring instructions rather than source heater lines & grounds from anywhere other than the controller (which presumably is part of your gauge mechanism?).

After my grief I resorted back to the KISS principle - Stock sensor doing the ECU (both banks and resistor to fake the missing heater circuit) and WB/gauge standalone for monitoring. But my O2s are side by side and not in-line. s:? :? s:?

None of this may help, but hope it focusses your fuzzy head a bit.

The only final piece of advice I can offer is do not under any circumstances try to make a decision until your head is clear - its tough enough when you're sober s:wink: :wink: s:wink: Good Luck!

Ste

*edit - Aaron put it so much better! .... except the WB does have a heater element.

*edit again - Aaron has just removed that claim from his post s:wink: :wink: s:wink: but I wouldn't feed this from the stock O2 socket for the reasons stated above .... somewhere.

aaronjb · February 25, 2007, 11:36

Quote from: "spit"*edit - Aaron put it so much better! .... except the WB does have a heater element.

*edit again - Aaron has just removed that claim from his post s:wink: :wink: s:wink:

Yeah - I edited that bit when I realised what 'H-' and 'H+' were on the diagram.. whoops! I'm clearly not awake yet s;)

s;)

Good info about the start-up checks, though - I hadn't thought about that, and you could well be right (after all, the stock ECU does the same checks on it's NB sensors, so it's logical to assume that aftermarket WB controllers would do the same heater checks on their sensors too)

spit · February 25, 2007, 11:48

Yes, in which case leaving those open circuit by feeding the heater element from elsewhere just won't work.

I'd be VERY surprised if any decent WB setup performs a calibration in advance of a confirmed heat-up cycle.

Anonymous · February 25, 2007, 12:19

right then......... I'll read this again later (when level headed s:lol: :lol: s:lol: ) but I think I've registered a few good points there.

feed from the new sensor wont work with ECU as it hasnt gone thruogh the controller yet, so I need to run the 0-5v feed back to the ecu from the back of the gauge

to remove the last stock sensor completely will be done easiest by repeating the process for the first one (ie heat sink etc) and using the signal feed from the gauge (post controller)..yes?

I'm assuming I will need to use a second heat sink as the initial onewill only fool the ecu into thinking one heater is operational and not upto replacing two stock sensors?

thanks for this guys, helps when you can air these things when fuddled s;)

s;)

aaronjb · February 25, 2007, 12:24

Yep I think you have it s;)

s;)

Replace existing ECU with a second heater-fooler circuit (you're right, the first would probably spontaneously combust s;)

s;) )
Run wiring from new WB O2 to guage
Run narrowband feed from back of guage to ECU

Sounds like a 5 minute job when you put it like that, doesn't it! s;)

s;)

spit · February 25, 2007, 12:28

0-1v on ours, not 0-5v.

This'll be neat when its done - one resistor/heatsink on each connector in the engine bay and the rest indoors.

Nice s8)

s8)

(PS signal wires are pins 12 and 21 on the E4 plug of the ECU)

Anonymous · February 25, 2007, 15:56

cheers chaps s:)

s:)

in regards to setting the right calibration for our ECU's, there is a small screw at the back of the gauge/controller, this allows the following settings (analogue output)

P0 (default) = guage displays AFR
P1 = gauge displays Lambda

P0 & P1 implement a linear calibration with the most useful voltage range possible (0-5v)

P2 = AFR calibration, linear and similar to P1, smaller voltage range (1-2v)

P3 = AFR calibration emulates the autronic wideband o2 sensor calibration (0-1v)

P4 = AFR calibration, emulates a non linear nernst cell calibration (0-1v)

so we must be talking P3 or P4 for our ECU's ??

aaronjb · February 25, 2007, 16:03

P4 (standard nonlinear Nernst Cell sensors are the type which pretty much switch instantly from ~1V to ~0V around 14.7:1 AFR)

spit · February 25, 2007, 16:22

*eagerly awaits Perry's next post hoping it doesn't include words like Bang, Smoke and Melt*

aaronjb · February 25, 2007, 16:37

Quote from: "spit"*eagerly awaits Perry's next post hoping it doesn't include words like Bang, Smoke and Melt*

Hopefully not indeed!

Anonymous · March 10, 2007, 14:57

well just to update, no smoke or sparks so far s:)

s:)

old gauges (well they've done around 5 miles s:lol: :lol: s:lol: ) now out and back on the bench and new AEM gauges in s:)

s:)

OUT

IN

forgot to take a piccy of the cluster, but the new AEM ones match nicely with taurecs dials

AFR gauge is connected and runnning the ECU, boost gauge will be connected up this afternoon, oil pressure will be connected during the week when I have time to drop the oil

a good half days work s:)

s:) back to proper 'work' work now (report to write s:(

s:( )

loadswine · March 10, 2007, 16:37

Those gauges look the biz! I like the AEM stuff, nice orange treatment. I think I'd be disappointed if they weren't orange! s:)

s:)

Anonymous · March 10, 2007, 16:42

They do appear to be top quality matey, only thing is that they protrude further out than the likes of autometer or autogauge so would look a bit odd if against others of a different sort.

look great tho in comparrison s:)

s:) (should be at that price! s:shock: :shock: s:shock: )

big question is..............................is yours going to be red ? s;)

s;)

loadswine · March 10, 2007, 17:08

Nice thought , I wouldn't know how to make them red! Plus I have 2 different makes of gauge. I have the AEM AFR gauge and Autogauge boost and egt. I figured I'd put the AEM in the centre and it wouldn't look so odd. The other 2 kinda match.
Got to get a gauge pod this week, nothing special, just a triple, loads on ebay.

Anonymous · March 10, 2007, 17:50

cool s:)

s:) if you change your mind and go for more AEM gear then just stick the faces in the post and they'll be red by return s;)

s;) s:)

s:)

things arnt going so well this end after all, after initially starting the car (after ensuring the controller is set to 'P04') she ticked over nicely

now she wont tick over at all without using the accelerator to bump up the revs s:(

s:( going to try wiring the stock o2 sensor back in to see if that makes the difference?

luckily I put connectors on the signal wire incase the wideband ever packed in due to heat etc.

cant seewhy it would be a problem tho as its set to P04 which is 0-1v same as stock???

heathstimpson · March 10, 2007, 20:45

Does this mean you have some old gauges for sale Perry s:?: :?: s:?: s:wink: :wink: s:wink: (vulture mode on)

Anonymous · March 10, 2007, 20:54

I have :-

boost
oil pressure
oil temp
voltage

I'm just waiting on fitting the new oil pressure sensor in a sandwhich plate I have sitting in the garage, if this plate fits ok then the gauges will come with sandwhich plate already 'plumbed' in so to speak

this sort but in 52mm

m http://cgi.ebay.co.uk/GAUGEPLACE-STEALT ... dZViewItem m

heathstimpson · March 10, 2007, 22:49

Quote from: "perry190"I have :-

boost
oil pressure
oil temp
voltage

I'm just waiting on fitting the new oil pressure sensor in a sandwhich plate I have sitting in the garage, if this plate fits ok then the gauges will come with sandwhich plate already 'plumbed' in so to speak

this sort but in 52mm

m http://cgi.ebay.co.uk/GAUGEPLACE-STEALT ... dZViewItem m

Just let me know when its sorted matey; cheers s:wink: :wink: s:wink: