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Technical => Wiring & Sensors => Topic started by: lost on May 08, 2016, 08:52:26 AM

Title: wideband wont read below 0.86 lambda
Post by: lost on May 08, 2016, 08:52:26 AM
I have vems 3.5, and wideband lsu 4.2, it wont read below 0.86 lambda on idle...

If i left it to idle on 0.92 for 10 seconds, it stops reading...

So i cant calibrate injectors, changed big 870cc that had 1.4ms on idle  back to 189cc stock bosch  0 280 150 702

https://youtu.be/A5j-Fg4hmcM (https://youtu.be/A5j-Fg4hmcM)
Here is video...
Title: Re: wideband wont read below 0.86 lambda
Post by: lost on May 08, 2016, 03:31:31 PM
I just recalibrated wideband and ecu nerst /pump, and its still the same, wbo2 wont read richer than 0.9 on idle.....
Title: Re: wideband wont read below 0.86 lambda
Post by: VEMS on May 09, 2016, 04:08:10 PM
Hello Lost,

If it was working without problems before, its most likely sensor failure; replace it.

Best regards, Dave
Title: Re: wideband wont read below 0.86 lambda
Post by: lost on May 10, 2016, 10:14:07 AM
It can measure 0.7 lambda while driving the car,

While calibrating lsu 4.2 i measured :
88 ohm Rcal on sensor,
145 o2 calibration


and with 100 ohm resistors and led:

4v between pump- and gnd
0v between pump + and - (100 in vemstune)
+450mV nerst and pump - (136 in vemstune)

, do you know if RI target is 165 in vemstune for old LSU 4.2 ? Or i have wrong value here?


Procedure followed : http://www.vems.hu/wiki/index.php?page=GenBoard/Manual/WideBandHardwareTest
Title: Re: wideband wont read below 0.86 lambda
Post by: VEMS on May 10, 2016, 10:47:39 AM
Quote from: lost on May 10, 2016, 10:14:07 AM
It can measure 0.7 lambda while driving the car,

While calibrating lsu 4.2 i measured :
88 ohm Rcal on sensor,
145 o2 calibration


and with 100 ohm resistors and led:

4v between pump- and gnd
0v between pump + and - (100 in vemstune)
+450mV nerst and pump - (136 in vemstune)

, do you know if RI target is 165 in vemstune for old LSU 4.2 ? Or i have wrong value here?


Procedure followed : http://www.vems.hu/wiki/index.php?page=GenBoard/Manual/WideBandHardwareTest
Your test values are good, 165 is indeed Ri target for both LSU 4.2 and LSU 4.9, still everything pointing to BAD SENSOR, replace it.

Best regards, Dave
Title: Re: wideband wont read below 0.86 lambda
Post by: lost on August 14, 2016, 03:46:39 PM
After replacing sensor with LSU 4.9 everything works OK!