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  • #16
    I bet you would go on too, but I will cut you short by just cutting and pasting the origional question..

    hey guys., whats going on? what is the typical average afr at idle?
    Aceman, don't waste my time.
    Try not to be a Yahoo

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    • #17
      I also tested the timing with and without the TPS. During warmup, it does make a difference. It was maybe 5 degrees or so, but once warmed up, there appeared to be no difference in timing. But taking off the TPS does make the idle awful.
      Try not to be a Yahoo

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      • #18
        crowbar wrote: I also tested the timing with and without the TPS. During warmup, it does make a difference. It was maybe 5 degrees or so, but once warmed up, there appeared to be no difference in timing. But taking off the TPS does make the idle awful.
        and as you know the cold timing was modified becuase of the chts signal, good of you to point that out bob

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        • #19
          Don't mention it Shirley.
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          • #20
            crowbar wrote: But taking off the TPS does make the idle awful.
            thats because the ECCS is now in closed loop and using the 02 sensor to correct the AFRs at idle, making the idle speed surge up and down.
            [strike:ff0tp92h]1984 300ZXT[/strike:ff0tp92h]
            [strike:ff0tp92h]1986 300ZX 2x2 NA2T[/strike:ff0tp92h]
            2000 Porsche Boxster
            2007 Toyota Yaris

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            • #21
              True. Idle is sort of a open loop condition in regards to O2 sensor.

              But the original question stands, what is the afr at idle?
              Try not to be a Yahoo

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              • #22
                crowbar wrote: True. Idle is sort of a open loop condition in regards to O2 sensor.

                But the original question stands, what is the afr at idle?
                Hook up a wideband, find out, spread the word.

                Or at least someone do it. We all want to know.

                oh, and tell us what you TTPmin is, 'cause that makes a big difference in idle mixture.
                [strike:ff0tp92h]1984 300ZXT[/strike:ff0tp92h]
                [strike:ff0tp92h]1986 300ZX 2x2 NA2T[/strike:ff0tp92h]
                2000 Porsche Boxster
                2007 Toyota Yaris

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                • #23
                  You wouldn't need a wideband really. In the leaner spectrum, most afr meters would be accurate enough.
                  Try not to be a Yahoo

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                  • #24
                    crowbar wrote: You wouldn't need a wideband really. In the leaner spectrum, most afr meters would be accurate enough.
                    Exactly how would you know what afr it was with a narrowband O2 that is "accurate enough"?
                    http://z31performance.com/forum/viewtopic.php?f=5&t=147

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                    • #25
                      I would use the basic principles of precision; repeatability, accuracy and resolution. What 'Exactly' would you use?
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                      • #26
                        crowbar wrote: You wouldn't need a wideband really. In the leaner spectrum, most afr meters would be accurate enough.
                        yea, sure.. try taking a look at an output voltage vs. afr graph of a normal o2 sensor..

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                        • #27
                          crowbar wrote: I would use the basic principles of precision; repeatability, accuracy and resolution. What 'Exactly' would you use?
                          No, seriously. What are you suggesting is used in order to determine the exact afr? Withing a .5 resolution lets say. Give us real details of the hardware and any peripheral components that would help provide the output to a human readable format.

                          *edit* I'm going to lock this. The conversation is not going in a direction which will lead to the question being answered. If anyone actually has some insight or useful information that should be added to this thread, PM me and I will add it to the thread.

                          I'm done with mindless bickering. Quit it or face the rath of me deleting entire threads when you do it.
                          http://z31performance.com/forum/viewtopic.php?f=5&t=147

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                          • #28
                            I think I can sum this entire thread up pretty simply:

                            1. Post warmup, the timing maps for idle and timing at the cells at idle speed in the main map are both the same. Hence, if the engine is warm and at idle, TIMING will be the same in either TPS position. Both also should have the same AFR which IS closed loop at idle when the engine is warm. Whoop, AFR at idle should be around stoich if closed loop is active with a good O2 sensor.

                            2. Most narrowband sensors, even when brand new, don't cycle fast enough for smooth and unfluctuating AFR at idle if the fueling is very much different from what they (nissan/jecs) calibrated. This is the one way titania sensors are superior; faster feedback. They also don't have the resolution you would need to measure AFR's very far from 14.7, but they ARE accurate right around 14.7 so they can be used for diagnosis at the very least. You would not need a zirc wide spectrum (AKA wideband) sensor for this.

                            3. All the rest I see is a bunch of senseless bickering. Crowbar, post your information and let's all take an objective look at it. I'm not saying anybody is in the right or wrong, just that I don't understand what you are trying top prove. Let's see it.

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                            • #29
                              SupSay Z wrote: hey guys., whats going on? what is the typical average afr at idle? im around 14.7 but smell a little rich. what do you guys read? thanx..

                              alex
                              Sup

                              Please show how you measured the afr. You mention 14.7:1 and then 14.5:1? Do you have some sort of wideband system? Is the origional O2 sensor still present or gone (replaced by something else). Do you have a good reason to believe you have an accurate system?

                              Thanks
                              Lew
                              Try not to be a Yahoo

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                              • #30
                                Jason

                                I would appreciate it if you would re-instate the thread that OR-ZMNAN deleted so I can cut and paste my work.

                                Thanks
                                Lew
                                Try not to be a Yahoo

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