Mgrene Posted March 20, 2014 Share Posted March 20, 2014 (edited) Good evening. I have just relocated my AEM air/fuel gauge and since then it has been acting weird. The car is right now in my garage for winter storage, when I leave the garage I always disconnect the battery. Here is the problem. When I connect the battery and start up the car, my AEM gauge is "freezing" on 14,8 even though I am playing a bit with the gas pedal. I need to tap/adjust a few times on the gauge before it reacts. After that it works fine. If I then shut down the engine and start it up again, it also works fine. What is going on? It has not been acting like this before. Anybody experinced the same? I have a great video which exactly shows the problem but I do not know how to upload the video? Edited March 20, 2014 by Mgrene (see edit history) Quote Link to comment Share on other sites More sharing options...
Ric Posted March 20, 2014 Share Posted March 20, 2014 Do they take a few blips to calibrate after power disconnection? Quote Link to comment Share on other sites More sharing options...
Mgrene Posted March 20, 2014 Author Share Posted March 20, 2014 Do they take a few blips to calibrate after power disconnection? To be honest I haven't noticed if it does or not? Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 20, 2014 Share Posted March 20, 2014 Before you start the car you should see it swing all the way around from 10 -18 but displaying --- where the numbers would be and then it should go to a solid 14.8 as its heating then lean out , then when you start the car it will then read correctly, Its probably just a heating thing mate Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 20, 2014 Share Posted March 20, 2014 Thats what it does if the sensor isn't connected, make sure the plug at the back is connected properly. Quote Link to comment Share on other sites More sharing options...
Mgrene Posted March 20, 2014 Author Share Posted March 20, 2014 Before you start the car you should see it swing all the way around from 10 -18 but displaying --- where the numbers would be and then it should go to a solid 14.8 as its heating then lean out , then when you start the car it will then read correctly, Its probably just a heating thing mate Maybe that is what I'm doing wrong. When i insert the key, I start the car immediately which mean that I don't wait for it to swing from 10 to 18 and afterwards display --- But it hasn't been a problem earlier so strange it is starting to do that now. And even more strange that it starts functioning correctly when I adjust the gauge itself a little bit. I would really like to show you the film but still don't know how to upload :-( EDIT: But maybe I should wait for it to run it's starting program before I start the car? Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 21, 2014 Share Posted March 21, 2014 seems to be a long time for it to be at the 14.8 heat up cycle , and if your messing around with it and it starts i woukld say its got a loose connection or bad earth Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 21, 2014 Share Posted March 21, 2014 Ill just talk to myself then lol. Also check the plug from the gauge harness to the sensor. Quote Link to comment Share on other sites More sharing options...
Nodalmighty Posted March 21, 2014 Share Posted March 21, 2014 (edited) It's the sensor's heater warming the sensor up to temp. If it's from a cold start them it will take longer. Hot start, should be very quick if not instant. The sensors really don't like being exposed to exhaust gas until the heater is up to full temperature as this can shorten there life span. Lyndon. Edited March 21, 2014 by Nodalmighty (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 21, 2014 Share Posted March 21, 2014 a video from the very start would help ie.first turn of the key as the afr is turnt on Quote Link to comment Share on other sites More sharing options...
Mgrene Posted March 21, 2014 Author Share Posted March 21, 2014 It's the sensor's heater warming the sensor up to temp. If it's from a cold start them it will take longer. Hot start, should be very quick if not instant. The sensors really don't like being exposed to exhaust gas until the heater is up to full temperature as this can shorten there life span. Lyndon. So you conclude that I should warm up the censor before i start the car. I will try this later today and make a video of it also. I will also check the harness in rhe engine bay and the wiring behind the gauge. I just still think it is strange that it reacts when i physically touch the gauge itself. It must be some kind of loose connection but if that is the case then it shouldn't work at all, because when I touch it, it is very limited how much I adjust it. Jesus! The more you think about it the more questions you will raise. God damn electronics! Quote Link to comment Share on other sites More sharing options...
Nodalmighty Posted March 21, 2014 Share Posted March 21, 2014 If you are pressing, i.e exerting some force on the unit and it starts to work then you have a contact issue either inside the unit or in the connectors like Swampy442 said. I've had to pull one apart to fix it in the past and they are a bit flimsy inside. Lyndon. Quote Link to comment Share on other sites More sharing options...
Fly Posted March 21, 2014 Share Posted March 21, 2014 Not AEM but my Innovate states that there is no requirment to prewarm the sensor prior to staring the engine. Sounds like a connection problem Quote Link to comment Share on other sites More sharing options...
Whitesupra95 Posted March 21, 2014 Share Posted March 21, 2014 All wideband sensors need to heat up before the give you readings, you don't have to wait to switch on the car but if you do just start it straight away you will not get a proper reading till it's warmed up. They can sometimes take over 20secs from cold to heat up fully. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 21, 2014 Share Posted March 21, 2014 In my experience (last week as my car is in bits) when the gauge powers up without the sensor plug connected, it just sits at 14.8. Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 21, 2014 Share Posted March 21, 2014 In my experience (last week as my car is in bits) when the gauge powers up without the sensor plug connected, it just sits at 14.8. This is true its how you check calibration to a ecu , but they do still have to warm up Quote Link to comment Share on other sites More sharing options...
TT Paul Posted March 21, 2014 Share Posted March 21, 2014 mine reading is fully lean with ign on, and starts reading pretty much as soon as eng starts, had 2 aems on 2 supras both work about the same. Quote Link to comment Share on other sites More sharing options...
Mgrene Posted March 21, 2014 Author Share Posted March 21, 2014 Well guys. I checked the harness (for the censor) at the engine bay. Made sure it was fully plugged in. After that I checked the wires behind th gauge, mounted the dash back together and wupti, it works as it should. So it could be a loose connection, I guess we never know :-/ It was not obvious that a wire was loose. From now on I let the gauge run it's "starting" program (takes only a few seconds) before I start the engine. [video=youtube;Vk-8YOj2S9k] Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 22, 2014 Share Posted March 22, 2014 Well guys. I checked the harness (for the censor) at the engine bay. Made sure it was fully plugged in. After that I checked the wires behind th gauge, mounted the dash back together and wupti, it works as it should. So it could be a loose connection, I guess we never know :-/ It was not obvious that a wire was loose. From now on I let the gauge run it's "starting" program (takes only a few seconds) before I start the engine. You dont need to let it complete its start up cycle before you start , as the way you have it wired in starting the car cuts its power anyway so it has to do it again , but glad its sorted Quote Link to comment Share on other sites More sharing options...
mikefinan Posted March 22, 2014 Share Posted March 22, 2014 Well guys. I checked the harness (for the censor) at the engine bay. Made sure it was fully plugged in. After that I checked the wires behind th gauge, mounted the dash back together and wupti, it works as it should. So it could be a loose connection, I guess we never know :-/ It was not obvious that a wire was loose. From now on I let the gauge run it's "starting" program (takes only a few seconds) before I start the engine. not sure if your aware but if your car is fitted with an airbag and you disconnect the top dash panel with the warning lights either side you will activate the airbag warning light.....just a heads up Quote Link to comment Share on other sites More sharing options...
james_cbr Posted March 22, 2014 Share Posted March 22, 2014 strange your heater lights don't light up for a while mine come on soon as key is turned Quote Link to comment Share on other sites More sharing options...
Mgrene Posted March 22, 2014 Author Share Posted March 22, 2014 There are no airbag installed, but thanks for the concern. Quote Link to comment Share on other sites More sharing options...
Mgrene Posted March 22, 2014 Author Share Posted March 22, 2014 strange your heater lights don't light up for a while mine come on soon as key is turned They do not light up before I turn on the switch on the signal arm. Hihi apparently for some reasom I chose to do that in the middle of the video. Quote Link to comment Share on other sites More sharing options...
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