AnWaRi996 Posted April 11, 2021 Report Share Posted April 11, 2021 Hey all, I'm having trouble diagnosing a horrendous running car. As soon as it starts up idle ramps up to 1600 and it blows obscene amounts of black smoke. The plugs are sooty and it's misfiring but I'm not sure what I'm meant to be looking for in the logs (which are attached) I've noticed the O2 sensor on AN Volt 4 doesn't ever show a reading other than 0.0v although my understanding is that it should cycle between 0.0 and 0.7, which would mean that the car is only seeing a lean mixture. Could this then be a result of a faulty o2? Otherwise i'm not really sure how to interpret the log to diagnose the current issue. Really just unsure of what the ecu is seeing that is causing it to act this way and any insight would be amazing! 602985825_richrunandmisfire.llg Quote Link to comment Share on other sites More sharing options...
dx4picco Posted April 11, 2021 Report Share Posted April 11, 2021 Do you only have the stock 02 sensor in the car or did you put an aftermarket wideband O2 sensor? If you only have a stock one then I would recommend you to get a wideband to really know what is going on Quote Link to comment Share on other sites More sharing options...
AnWaRi996 Posted April 11, 2021 Author Report Share Posted April 11, 2021 17 minutes ago, dx4picco said: Do you only have the stock 02 sensor in the car or did you put an aftermarket wideband O2 sensor? If you only have a stock one then I would recommend you to get a wideband to really know what is going on Yeah I'm just running the stock O2 right now. Later down the track I will, but surely it should show something irregular at the moment. Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 11, 2021 Report Share Posted April 11, 2021 Has it been tuned and was it previously running ok? Stock O2 sensors wont do anything unless you have already tuned it and set up closed loop lambda in stoich mode. Quote Link to comment Share on other sites More sharing options...
AnWaRi996 Posted April 11, 2021 Author Report Share Posted April 11, 2021 Just now, Adamw said: Has it been tuned and was it previously running ok? Stock O2 sensors wont do anything unless you have already tuned it and set up closed loop lambda in stoich mode. The car has already been tuned and was running great beforehand Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 11, 2021 Report Share Posted April 11, 2021 There doesnt appear to be anything obviously out of place in the log. If the idle RPM is higher than it was previously that suggests there is an air leak. Quote Link to comment Share on other sites More sharing options...
AnWaRi996 Posted April 11, 2021 Author Report Share Posted April 11, 2021 1 hour ago, Adamw said: There doesnt appear to be anything obviously out of place in the log. If the idle RPM is higher than it was previously that suggests there is an air leak. That's what I was leaning towards, are we able to take an educated guess on whether its the intake or exhaust side of the engine due to the symptoms? or just an air leak anywhere post IAT and pre O2? I have a feeling it's bent valves but a compression test later in the week will determine that. Quote Link to comment Share on other sites More sharing options...
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