2G Chasing grounds

[KFred 513]

I'm having a big problem with my car going lean. More can be found here http://www.dsmtuners.com/threads/lean-under-any-load.488344/

After troubleshooting every fuel system component I'm starting to look into wiring and grounding issues. I have verified all sensors have proper ground with the exception of the O2 sensors.

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The O2 sensors are the only concern I have as far as that goes. I have an AEM UEGO and I'm wondering if it gets grounded to pin 92 (sensor ground) at the ecu. The OEM green shielded wire runs to my gauge, not the sensor, and the sensor ground wire is not connected to anything. The white signal wire runs into the back of the gauge. I made a quick diagram to show my situation.

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The aem directions just mention grounding the unit to chassis during install. Does this mean the sensor ground is left unused as mine is?

 

[jimsgsx]

Just a thought. Have you verified that gas is actually making its way through the injectors to the engine. I just read your thread and sounds like maybe a bad electrical connector on one of them.

 

[KFred 513]

well I am relying on the readings from the wideband, and the Front O2 that both indicate the mixture going lean. The condition is repeatable and consistent. Both sensors lean out at the same time. Based on this, I think its safe to say that the required amount of fuel is not making it from the rail to cylinders. I suppose It could be one bad connection/injector, but all spark plugs look the same. I also think that if one injector was the problem, I would be able to richen it up in the tune, but the mixture doesn't richen with any amount of fuel added. I could be wrong though, i'm not sure.

I read that Rx7 guys can have my problem from poor grounding to the ecu. The connection can supply a low amount of current, but as certain things demand a higher draw, the connection can't handle the load.