Warmup question for you with AFM gauges
05-25-2003, 07:51 AM
#1
Three Wheelin'
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Warmup question for you with AFM gauges
For you guys with A/f Meters....how soon do you notice your cars going into closed loop after you start a cold engine I.E 'dithering' ??
My car starts trying to adj the mixture even before there is a good signal from the O2 sensor and runs a bit rough, like about 20 seconds after start up. And runs this way for about 3 or 4 min before it smooths out.
It seems to me that the DME shouldnt go into closed loop until the engine is warmed up.
My car starts trying to adj the mixture even before there is a good signal from the O2 sensor and runs a bit rough, like about 20 seconds after start up. And runs this way for about 3 or 4 min before it smooths out.
It seems to me that the DME shouldnt go into closed loop until the engine is warmed up.
05-25-2003, 09:17 AM
#2
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Have you ever replaced the sensor?
Mine started to have activity after about 15 seconds, no running issues except with the temp compensation on my Huntley MAF.
If you are running stock gear, and it does not seem right, the O2 sensor could be on it's way, or you have other issues.
Mine started to have activity after about 15 seconds, no running issues except with the temp compensation on my Huntley MAF.
If you are running stock gear, and it does not seem right, the O2 sensor could be on it's way, or you have other issues.
05-25-2003, 01:45 PM
#3
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It takes a few minutes after a cold start before the dithering begins on my vehicle. Even after a warm restart, it's a minute or two before it goes back to dithering.
05-25-2003, 02:01 PM
#4
Nordschleife Master
I'm with John, it takes a minute or 2 before it starts dithering...I have a fresh (5k miles) Huntley 4 wire O2 sensor with the a/f gauge and O2 grounded to the battery.
I have the stock AFM...Car is chipped but that shouldn't have any effect.
Now that I think about it...my car runs really rich on cold startup...so that could be why I don't see dithering...I think its usually pegged on the rich scale of the A/F gauge...I dont remember though...I'll check it out next time I drive it.
I have the stock AFM...Car is chipped but that shouldn't have any effect.
Now that I think about it...my car runs really rich on cold startup...so that could be why I don't see dithering...I think its usually pegged on the rich scale of the A/F gauge...I dont remember though...I'll check it out next time I drive it.
05-25-2003, 02:37 PM
#5
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It takes me a few minutes of constant Stoich operation before the reading begins to dither. And When it does begin to dither, about a split second before it happens you can tell the engine pick up and slow down a bit as it goes back and forth from lean to stoich.
I would recomend upgrading your sensor as well.
My sensor was all fouled up and when i replaced it the engine ran extremelly good. Accurate reading as well.
I would recomend upgrading your sensor as well.
My sensor was all fouled up and when i replaced it the engine ran extremelly good. Accurate reading as well.
05-26-2003, 02:36 AM
#7
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If your O2 output does dither after the engine completely warms up, it is probably OK.
The DME will go into closed loop early if it thinks the engine is hot, so unless the O2 sensor output never dithers, check the DME water temp sensor.
The DME will go into closed loop early if it thinks the engine is hot, so unless the O2 sensor output never dithers, check the DME water temp sensor.