T14PPA Posted November 12, 2015 Share Posted November 12, 2015 I fitted a used aem wideband today and when i started it from cold was 15ish and then when warm it idled at 14.7. But everytime i touched a little throttle (not even enough to gain boost) it went to 16ish. Now i know its not going to be perfect as its not mapped yet but should it be running like that? Its got a gt40 dbb on it with Stock ecu and injectors. But ive not put my foot down. Its literally just used to cruise to my garage when i work on it before the map. Just want to make sure its working before map Quote Link to comment Share on other sites More sharing options...
Gpro Posted November 12, 2015 Share Posted November 12, 2015 (edited) touched throttle and let go swiftly or held the throttle to accelerate and AFR is 16?. Have you tried spooling the turbo to very low boost like 0.2 bar and see if the AFR starts to turn the other way? Regarding idle 14.7 is fine, but ideally it should be running richer when cold. Edited November 12, 2015 by Gpro (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 12, 2015 Share Posted November 12, 2015 The stock ecu does run lean with low rpm with first throttle press from idle , around 2000-2500 mine would go into late 15s but its at a point no boost is made , doubt its an issue as max economy is made at 16 afr , I expect its to do with mpg more then anything Quote Link to comment Share on other sites More sharing options...
T14PPA Posted November 12, 2015 Author Share Posted November 12, 2015 So you think the gauge is working fine? It might just need a map to work properly. I just saw the gauge go high so didnt really want to go any further with the throttle. Car runs lovely though Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 13, 2015 Share Posted November 13, 2015 Well you want know until you get it mapped. To confirm what readying the mapper gets Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 14, 2015 Share Posted November 14, 2015 Does the software for the AEM allow free air calibration of the sensor? I am not familiar with it, but my MOTEC PLM allows you to either use a MOTEC calibrated sensor, or a none calibrated sensor and calibrate it in free air. The proper test is to get a gas analyser calibration guy to put the sensor in several calibration gasses and check the readings. My pal is a Bosch calibration engineer, so it's easy for me, you would have to ask your MOT centre who calibrates their gas analyser. Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 14, 2015 Share Posted November 14, 2015 The aem is ment to do a self test everytime you add power, to check the aem gauge your ment to unplug and the display should show a specific fail I cant remember off the top of my head , but thats more to check the ecu matches the gauge. Its only when the sensor fails it would read wrong you tube has a couple of vids that show putting a fuel soaked rag around the sensor to make sure it stays reading rich Quote Link to comment Share on other sites More sharing options...
T14PPA Posted November 14, 2015 Author Share Posted November 14, 2015 The aem is ment to do a self test everytime you add power, to check the aem gauge your ment to unplug and the display should show a specific fail I cant remember off the top of my head , but thats more to check the ecu matches the gauge. Its only when the sensor fails it would read wrong you tube has a couple of vids that show putting a fuel soaked rag around the sensor to make sure it stays reading rich Yes i think i saw that. I might post a video up on here aswell to see if it looks normal Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 14, 2015 Share Posted November 14, 2015 Put a video with a cold start until idle drops that way you can see if the afr is correct with a cold start you should see low 12s high 11 maybe then it should drop off around 14.5 -15 fluctuating Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 14, 2015 Share Posted November 14, 2015 Won't it allow something like this, taken from my MOTEC PLM manual?: Calculate from O2 Concentration (Free Air) This calibration method uses the known oxygen concentration of free air to calibrate a sensor. Re-calibration using this method allows a sensor to maintain accuracy as it ages. To perform the free air calibration, the PLM must be powered up and connected to a PC (with a serial cable) running the PLM Setup software. The configuration in the PLM must match the sensor type being used for the calibration. Free air calibration must be done in the open air – not in a workshop or dyno room where there will be large amounts of hydrocarbons in the atmosphere. The O2 Concentration parameter specifies the actual % concentration of Oxygen in the atmosphere and should be entered if known. A nominal value of 20.94% is given, but the more accurately this is known for current atmospheric conditions (temperature, pressure) the more accurate the calibration will be. To start the calibration process, click the ‘Calibrate’ button. The following dialog is displayed while the sensor readings stabilize. When the sensor reading is stable the calibration can be stored by clicking the Store button, as shown below. The new calibration value is displayed as both a gain factor and an equivalent resistor calibration. This calibration can be recorded against the sensor serial number to allow the sensor to be used with another PLM unit by simply entering the calibration value. Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 14, 2015 Share Posted November 14, 2015 In short the uego aem arf gauge cant do this in its self, it does a self calibration every time, it fails when the sensor cant hold a stable reading over a very short period, Ie If you was WOT at 11.2 it would read that first off but then start to lean off as the sensor is bad Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted November 14, 2015 Share Posted November 14, 2015 IMO it would be a bit daft and inaccurate for a WB lambda sensor to re calibrate every time the car is started...think about it the sensor can only recalibrate properly in free air, so its OK if you have left the car overnight, but if its been run in the last couple of hours its going to still have exhaust gas in the pipework, so surly its not going to calibrate correctly, so unless it can read the presence of atmospheric air, it wouldn't calibrate? I think I prefer the Innovate method IE wait 24hs and then calibrate/or on long overrun where fueling is off on most cars. Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 14, 2015 Share Posted November 14, 2015 I have just reread my manual, sorry it doesnt do a calibration everytime it does a self check, its down to the actual sensor used that has some resistor fitted that eliminates the need for a free air self check Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 14, 2015 Share Posted November 14, 2015 I'm surprised at the lack of calibration software, but at least it gives me some succour about how much my darned PLM cost, and it's been 100% reliable in regular and diverse usage. If you don't want or need the latest and greatest wide band sensor it allows me to use older models that appear occasionally as brand new old stock on Ebay at very handy money, too Quote Link to comment Share on other sites More sharing options...
T14PPA Posted November 14, 2015 Author Share Posted November 14, 2015 Today the gauge showed differently. When i first started it it was rich around 11.5 and then when warm was around 14ish. Only when i went over 2k revs it went to over 15-16. So im guessing its calibrated and its probably correct untill i get it mapped Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 14, 2015 Share Posted November 14, 2015 Sounds completly normal mate , it will stay at 14.7 closed loop with part light throttle to quite high boost around 0.7 bar depnding on setup and road conditions so stay at very low boost until mapped . Quote Link to comment Share on other sites More sharing options...
T14PPA Posted November 14, 2015 Author Share Posted November 14, 2015 Sounds completly normal mate , it will stay at 14.7 closed loop with part light throttle to quite high boost around 0.7 bar depnding on setup and road conditions so stay at very low boost until mapped . Yes mate i will. Its hard to resist though lol. Thank you so much for your help. Quote Link to comment Share on other sites More sharing options...
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