I have managed to get my motronic style vems running my URQ build. My issue is that i seem to have a non functioning wideband lambda setup and i dont know why. I have tried 2 sensors and i get the same issues. The issue seems to be related to this vems unit, as when i plug in my second vems unit(econo plug style) from my URS4 lambda works fine with both sensors. It could also be an issue with the config obviously, or the lambda loom in the motronic style ecu. I cannot attach the config for some reason to this post.
What i get is lambda showing 1.83 for a short time then it goes full rich to 0.63. I know its not actually that rich as i removed the probe from the exhaust and left it in air and it does the same thing. Changing probe has NO effect. I cannot get vems to do a free air calibration. It just sticks at the heating stage.
I have followed these instructions
http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FWideBandHardwareTest I seem to have the readings that pages wants. What i did was test at the connection for my LSU 4.2 sensor with the sensor connected as i have a motronic connector ecu so the connections are different than that pages asks for. I connected the 2 100 ohm resistors as described and Measured the voltages. I didnt have a normal LED so i used an old 12v LED from a car alarm and it lit up when i enabled the Lambda calibration in software. Also the sensor does heat up when left for some time.
I have 4.14 volts from Pump - to Gnd.
I have -1.4 mV from pump - to pump + with Pump-PW-Zero set at 103
When testing for Nerst DC Target i get 0 volts until after about 30 seconds approx it jumps to 454mV. Adjusting Nernst dc target does nothing to vary this value.
The software came with the WBO2 cal set at 206, and i tried changing it to 150, but that made no difference. When the engine running i get the following voltages on the sensor plug relative to ground.
1. Nernst 4.5v
2. NA
3. battery 13.5 V
4. Heat - 12 v
5. Pump - 4 v
6. Pump + 12v
On my other ecu which is an econo seal with and adapter loom with separate WBO2 loom i get the following with a working WBO2 setup.
1. Nernst 4.5v
2. NA
3. battery 13.5 V
4. Heat - 3-10 v varying
5. Pump - 4 v
6. Pump + 4.9v
So it is possible that the wiring on my motronic style Vems is wrong, but how do i determine which pin is which? This is turning into an electronics project not a car build.... Is my description of the pins correct above??
Thanks in advance, des.
