Odd findings with AEM wideband o2 (35-8460) - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 06-17-2014, 06:35 PM   #1
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Nov 2013
Location: GA
Posts: 171
Total Cats: -154
Default Odd findings with AEM wideband o2 (35-8460)

I am really just completley stumped on this little thing? my readings in tuner studio are never matching, hindering me from tuning properly.
phil tobin that wrote the software for megalog viewer made me a new ini file that gave me an AFR calibration tool like the ms2/3 users get that linearly interpolated the gauge in tuner studio says to my physical gauge in the car.
it just seemed really odd to me that i was reading 17 AFR at 4.00 volts, that is almost an entire afr difference from what its supposed to be.

it just got me thinking that if somthing is not right at all with my WB


Directly from aem manual/instructions.
"An easy way to do this
is to disconnect the UEGO sensor from the
UEGO gauge. When in this state, the UEGO
gauge will output 2.35 volts. You can then
adjust the O2 #1 Gain until the O2 #1 Volt
s display in AEMPro reads 2.35 volts. "

So i did, with mega-squirt up and running and JUST the 4 pin part of the wire harness connected to the gauge, the gauge displayed 14.7-8 twitching the .7 and the .8 back and fourth very quickly and did not stop/settle.

TS SAYS: 15.0-.2 AFR (twitching)
and voltage on the o2 bank voltage is reading 2.6-2.63volts

also the small calibration switch on the back of my gauge is pointed diagonally up on the right side
(when looking at the gauge from the back directly in the middle)

ive been reasearching and twiddling with the thing for months and still cant get it completley right. I may take that next step and order a new sensor or just replace the system all together
zacktrotter_uncc is offline   Reply With Quote
Old 06-18-2014, 11:42 AM   #2
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Nov 2013
Location: GA
Posts: 171
Total Cats: -154
Default

10-20afr=10afr 10afr / 5v = 2afr/v
14.7 = 4.7afr 4.7=2.35 = 2 afr/v
so consistent 2afr/v when taking the afr reading -10

my reading when wideband is hooked up & tuner studio is on.
14.7 = 2.61 v thats 1.8 afr/v
also got a reading with 4.00v in ts and a displayed 17.2 afr on gauge
7.2/4 v thats 1.8 afr/v

so my best guess is that its reading .2v less than that,
or that its a 10-19afr unit/sensor? 1.8v per afr across the board comes to 19afr perfectly at 5v

i did at one point run the tech-edge sensor option, which is a 19afr sensor but it is 9-19 afr @ 5v that is still 10/5 = 2afr/v
zacktrotter_uncc is offline   Reply With Quote
Old 06-18-2014, 11:45 AM   #3
Junior Member
iTrader: (7)
 
Join Date: Mar 2013
Location: Des Moines, IA
Posts: 146
Total Cats: 35
Default

How do you have it grounded?
Scrambles is offline   Reply With Quote
Old 06-18-2014, 01:18 PM   #4
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Nov 2013
Location: GA
Posts: 171
Total Cats: -154
Default

the previous owner installed it.
on the passenger side of the firewall out of a hole comes the black wire with the loop that is held on to a small flange behind the intake with another wire running from that to the flange that is beside the throttle. also two other wires are grounded there. but im not 100% that that leads to the wideband, the guy wired the gauge into the A-pillar so unless i remove the dash i cant tell exactly were the thing is running
zacktrotter_uncc is offline   Reply With Quote
Old 06-18-2014, 01:40 PM   #5
Junior Member
iTrader: (7)
 
Join Date: Mar 2013
Location: Des Moines, IA
Posts: 146
Total Cats: 35
Default

I would find your ground wire coming from the WBO2 sensor and connect it directly to the MS ground right out the back of the ECU. That would at least take one variable out of your issue. It sounds like a shoddy wiring problem to me.

In the 'race prep' board there is a thread about high quality gauges, and some of the smarter people on this board talk about proper wiring practices. I found it really helpful when I wired up my MS, IAT, Rad Fan, and WBO2 last weekend.
Scrambles is offline   Reply With Quote
 
 
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:58 PM.