LC-1 Analog input into VEMS

[badjuju]

How would I go about setting this up?  For some reason I'm getting super sketchy readings from VEMS' wideband controller, and they cut out at random times, but plugging my LC-1 in lets me read the AFR off the digi outputs into my laptop.

[rob@vems.co.uk]

You can't use a Wideband input - the VEMS has a wideband controller that works on thousands of installs.
Find the problem on your installation rather than trying to work around it.

[GintsK]

I am agree with Rob regarding VEMS wideband.
From my experience VEMS built in WBO2 is much more reliable than LC1.

But for data-logging it is possible to wire up external wide-band unit. Just watch on your VEMS unit specification which pins are analogue inputs without pullup. And preferable with protection.
In newer firmwares you can even configure gauge and I think data-log channel for human readable values.
On older this can be done in data-logging software.

Gints

[mattias]

I agree with both of the above. And if you're getting sketchy readings, it's because they are. You could have something wrong with your injectors or ignition system, or could have fouled the sensor with oil or running too rich for too long.

[rob@vems.co.uk]

Or have a bad joint/broken wire, or a misconfiguration of the controller.

[mattias]

If you fail to calibrate the sensor in free air, you have a very basic problem somewhere. Start by testing that.

[badjuju]

Should have posted this a week ago...  I put this reply into another post and didn't get any responses, so I started looking at a different route.  This is a repost from here:
http://195.159.109.134/vemsuk/forum/index.php/topic,55.15.html

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I can't seem to get my o2 gauge to read anything at my calibration screen...

VEMStune .10.14 (2010.01.08)
1.1.7, running Mattias' config, modified for my own use:

Wideband Controller
---------------------
Warmup ABS          228
Max time at ABS       41.9
Fallback V               176
Retry after               24
Heater PID Ri Target 150
Heater KP                 70
Heater KI                  16
KD                           26
PID Int. Limit            128
Pump KP                   21
KI                            78
KD                             0
PID Int Limit             132
----------------------------

Base Setup\Engine Calibration:
----------------------
Pump Zero PW              100
Pump PID Nernst Target  134
WBO2 Sensor Calibration 100
----------------------------

WBo2 Calibration:
----------------------------
WBo2 Sensor Calibration  100


Running sanity check:
---------------------
X Table Header order            "launch rpm curve x values must be in strictly monotonous ascending...
X warmup_clt[9]                  "Please check warmup_clt[9]!
!  Tooth_wheel_twidth
     "please check tooth wheel twidth [0,1]
!  Shifcut and Launch            "please check shiftcut input!"
----------------------

Soo, I don't want to change anything about my tooth wheel width, since the motor runs great, but that's a different thread.

Just trying to get you guys as much data as I can about this.

the O2 sensor IS heating up.

Initially upon wiring this up, I wired up pins 2 and 4 crossed (read: pin 2 should be disconnected, pin 4 goes to pin 18 on EC18... I had pin 4 disconnected and pin 2 going to pin EC18).  This has been fixed.

I thought maybe this had fried my sensor, so I'm now running it with my friend's sensor installed, but i'm having the same issue.

Thanks for any advice you guys may have.

Also... There isn't by chance some output or input I have to enable in order to get my wideband to be recognised?

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I got it to recognize an 02 value once in a while...  It'll come on after about 45 seconds of VEMS being on, is this just the delay from power on until when the heater is up to temp?

It doesn't show me the o2 value every time, either.

After calibrating it (value of 174 = 20.9), I started the motor, and didn't get a lambda value, or an AFR value.  After about 8 seconds I shut the ignition off, and vems showed me a high value of about 1.75 Lambda and 17.0 for AFR... Is there some delay between starting and when it'll show me the values, and I just shut it off right as it gave a value?  I'm having some strange issues w all this, lol

When the shadowed peak needles hit 1.75 and 17.0, I had already had vems running for a bit, and I was getting 20.9% on the wbo2 calibration screen, then I closed the calib screen, started the motor, and got nothing on the gauges until after I had shut the motor off in about 5-7 seconds.

Update:

If I run the motor, it'll eventually show me my AFR and Lambda.  However, it cuts in and out, seemingly at random.

I'm checking my wiring (again), but aside from that, what could be causing it to cut out like this?

[GintsK]

Where you got your Pump Zero PW and Nernst target?
It is normal when lambda reading appears just after ~1minute after start-up.
With wbo2 calibration constant of 100 could be no readings. Usual range is 155...225.
Your engine idling now?

[badjuju]

engine hauls ass and stays around 12:1, according to my LC-1.

Pump Zero PW and Nernst Target came from an email a buddy of mine sent to me when he shipped me my unit.

[mattias]

Why did you at first write that the WBO2 sensor calibration value was 100 and then later 174 ? Confuses people trying to help.

Like Gints said, 174 is a more trustworthy value. It's usually 155 up to 225, if outside that range = you have a problem.

[badjuju]

Sorry, sensor calib was at 100 before I had it communicating, THEN I changed it to 174.

It cuts in and out a ton though, not reliable.  I've checked wiring four times now.  Is it possible the input was damaged when I had it wired wrong initially (ie switching pins 2 and 4)?

[GintsK]

I would sort out the cause this way:
First pump zero, and nernst target. Because both steps are ECU hardware checks too. Here you need "tool" - two 100Ohm resistors.
 Switch sensor calibration on (with sensor connected) and measure how heater voltage rises. Slowly from ~6V...10 or so.
At this point ECU is checked and good.
Then calibrate the sensor.
If O2 values goes rapidly up/down by more than 1% anyway, then go for new sensor.

Gints

[badjuju]

I've tried the sensors that came with both mine and my buddy's LC1s.  This isn't simply a config issue.  It'll read 13:1, and then stop reading anything at all.

[GintsK]

It can be that LC make sensors unusable. They uses completely different strategy to drive the sensor than BOSCH designed. I had similar case. My sensor witch works with LC did not work with Tech Edge anymore.

But anyway for first check is it possible to calibrate pump zero (very simple)
And nernst target (you can use Start Calibration in VEMSTUNE and measure voltage across two 100Ohm resistors after minute)

[rob@vems.co.uk]

In short you NEED to get the pump_pw and so on tested because there is ZERO chance that the developers will develop anything for any other wideband.
One of the reasons for this is that as the system has a full understanding of the sensor's state it will ignore readings that it has no confidence in, so if a missfire causes a rich mixture the system will not try to correct it and cause the fuelling to become unstable.
You dont get this with an external wideband.