Trouble shooting Wideband
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Joined: Oct 2004
Posts: 644
Likes: 15
From: Clarksville Tennessee
Trouble shooting Wideband
Does anyone have any idea what is causing my wideband read erratically at idle. I installed an AEM UEGO wide band (PN#30-4100)on my 85 vette. The install was quick easy. The problem is my read out on the gauge is erratic at idle. Thinking that I possibly have a exhaust leak at the collector near O2 sensor (TPIS LT with Y pipe), I lined some exhaust thermo wrap with an exhaust sealer and rapped it around the seam where the LT and Y pipe meet. I then placed a 3" wide exhaust band clamp over it and tighten as I possibly can and let it set for about three hours. I also added hi temp RTV silicone around the treads of the O2 sensor to seal the O2 bung. Hours later I started my car and the wide band gauge read steadily at 14.5 for about 1 to 2 minutes while idling and then it goes erratically from 13.1 to 15.1 with spikes as high as 17 while idling. What could be causing this if my jerry-rig seal is working? I have a data log.
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Joined: Feb 2010
Posts: 677
Likes: 3
From: Metairie LA
Mine is erratic at idle.
This is how I look at it: the wideband is much more accurate than a narrow band. Ever watch a narrow band readout in a data log? It should be constantly going up and down around .450 volts during closed loop operation. If your ECM is controlling the fueling and spark advance (closed loop operation) your wideband is also seeing this "swing".
During the first minute or so of engine running mine is pretty steady (open loop operation). The ECM is not adjusting anything yet.
Hope this helps. Sometimes I wish I had never installed one - it will drive you crazy especially when tuning low speed/low load. It's very useful for full throttle.
This is how I look at it: the wideband is much more accurate than a narrow band. Ever watch a narrow band readout in a data log? It should be constantly going up and down around .450 volts during closed loop operation. If your ECM is controlling the fueling and spark advance (closed loop operation) your wideband is also seeing this "swing".
During the first minute or so of engine running mine is pretty steady (open loop operation). The ECM is not adjusting anything yet.
Hope this helps. Sometimes I wish I had never installed one - it will drive you crazy especially when tuning low speed/low load. It's very useful for full throttle.
Thread Starter
Pro
Joined: Oct 2004
Posts: 644
Likes: 15
From: Clarksville Tennessee
Mine is erratic at idle.
This is how I look at it: the wideband is much more accurate than a narrow band. Ever watch a narrow band readout in a data log? It should be constantly going up and down around .450 volts during closed loop operation. If your ECM is controlling the fueling and spark advance (closed loop operation) your wideband is also seeing this "swing".
During the first minute or so of engine running mine is pretty steady (open loop operation). The ECM is not adjusting anything yet.
Hope this helps. Sometimes I wish I had never installed one - it will drive you crazy especially when tuning low speed/low load. It's very useful for full throttle.
This is how I look at it: the wideband is much more accurate than a narrow band. Ever watch a narrow band readout in a data log? It should be constantly going up and down around .450 volts during closed loop operation. If your ECM is controlling the fueling and spark advance (closed loop operation) your wideband is also seeing this "swing".
During the first minute or so of engine running mine is pretty steady (open loop operation). The ECM is not adjusting anything yet.
Hope this helps. Sometimes I wish I had never installed one - it will drive you crazy especially when tuning low speed/low load. It's very useful for full throttle.
I see you live in Metairie. I grew up on the WestBank (westwego). I maybe making a trip down there next month to visit my parents.
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Joined: Feb 2010
Posts: 677
Likes: 3
From: Metairie LA
Awww damn, a "Westbanker". Coming down here with the Vette?
I did find a problem with my valves on one side (passenger long tube collector) thanks to said wideband. Posted a thread about my issues a while back. Wideband was always lean while BLM was always rich.
Think the Vette is finally ready to cruise (after two and a half years).
I did find a problem with my valves on one side (passenger long tube collector) thanks to said wideband. Posted a thread about my issues a while back. Wideband was always lean while BLM was always rich.
Think the Vette is finally ready to cruise (after two and a half years).
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Joined: Oct 2004
Posts: 644
Likes: 15
From: Clarksville Tennessee
Most likely I'll be driving the C5 for the trip. I'm not ready to put the 85 and such a long trip just yet. The last time I drove the C4 to New Orleans was in 2005 months after Katrina. Since then I have added some mods.
