Nurzh_rt Posted July 10, 2018 Report Share Posted July 10, 2018 Hello we have some problem with AFR at idle, above 1-2 hour lambda reads AFR 10-11 at idle and its really rich (tested with external wideband) But if we turn off engine for 30min, than AFR is ok, but only for 1 hour ECT, IAT, charge temp, ecu temp, Bat volt, Inj PW actual and effective all same may be its fuel temp but usually must be lean idle lean after 30 min Log 2018-07-10 8;34;51 pm.llg Idle rich AFR Log 2018-07-10 7;00;47 pm.llg Quote Link to comment Share on other sites More sharing options...
neil brown Posted July 10, 2018 Report Share Posted July 10, 2018 Failing lambda ? is it a wide band or narrow band what car Quote Link to comment Share on other sites More sharing options...
Nurzh_rt Posted July 11, 2018 Author Report Share Posted July 11, 2018 4 hours ago, neil brown said: Failing lambda ? is it a wide band or narrow band what car 4.9 on board and addition external aem x-series Quote Link to comment Share on other sites More sharing options...
neil brown Posted July 11, 2018 Report Share Posted July 11, 2018 ok as been ruing a lc1 wideband and now and again the wideband controller failed to boot up and fuel ratio stuck at 7:1 until i restarted the ar and went back to normal has happened twice in 3 years Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 11, 2018 Report Share Posted July 11, 2018 Pretty odd problem for sure. You have a mixture difference of 25% so that is a significant change in fuel or air mass. I dont see anything in the log that could cause that. Does it actually run completely different or does it still run ok when rich Vs normal? What injectors are they? If they are the Bosch CNG injectors then I would be suspicious of those. Have you checked fuel pressure? What about a tight valve clearance or vacuum leak or similar that causes 1 cylinder to misfire? Quote Link to comment Share on other sites More sharing options...
Nurzh_rt Posted July 11, 2018 Author Report Share Posted July 11, 2018 4 hours ago, Adamw said: Pretty odd problem for sure. You have a mixture difference of 25% so that is a significant change in fuel or air mass. I dont see anything in the log that could cause that. Does it actually run completely different or does it still run ok when rich Vs normal? What injectors are they? If they are the Bosch CNG injectors then I would be suspicious of those. Have you checked fuel pressure? What about a tight valve clearance or vacuum leak or similar that causes 1 cylinder to misfire? When its rich its really rich, with black smoke from exhaust Injectors is Delphi 42lb 01d030b high impedance still not checked FP i will check leak test later Quote Link to comment Share on other sites More sharing options...
Sheik Posted July 12, 2018 Report Share Posted July 12, 2018 Following - I have similar but less dramatic symptoms myself and have the same setup (onboard LSU 4.9 digital wideband). Mine has swings from around 0.97 down to sometimes ~0.91 after running for a while. I have pressure and temp data from fuel and oil so I have a little more to work with. Ultimately, I am chalking it down to not having proper data for my injectors. They are running at 1.4% DC (similar to what your log is showing) at idle and I dont think its possible for the pull enough fuel out when responding to fuel temp/intake charge temp. Due to it still being quite within reason and not generating any negative effects (poor idle/smoke/etc), I can ignore it in my case, but what you are facing sounds more significant. Just giving you an idea of what I logged and observed when trying to resolve the issue myself. Quote Link to comment Share on other sites More sharing options...
Krystian Posted November 26, 2021 Report Share Posted November 26, 2021 Did you ever found the problem? I have similar problem on my evo8 with link g4x ecu. When I restart the car air fuel change 1.0 point towards lean across whole fuel map but when I restart it again its coming back to normal. Quote Link to comment Share on other sites More sharing options...
Nurzh_rt Posted November 26, 2021 Author Report Share Posted November 26, 2021 4 minutes ago, Krystian said: Did you ever found the problem? I have similar problem on my evo8 with link g4x ecu. When I restart the car air fuel change 1.0 point towards lean across whole fuel map but when I restart it again its coming back to normal. SUre, it was injectors. just installed id1050x and no problems Quote Link to comment Share on other sites More sharing options...
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