Off to the track tomorrow...any helpful hints?
#46
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Originally Posted by silverG2007
During WOT and Power Enrichment mode (depends on throttle position and RPM, you go from stoich 14.7:1 A/F to about 12.5:1) it is in Open loop. The car ignores o2 feedback and calculates a/f ratio based on tables.
stock o2 sensors aren't accurate when cold or during WOT. You can buy wideband o2 sensors that'll give accurate readings during WOT and use them for tuning. But, the car will still be in open loop.
stock o2 sensors aren't accurate when cold or during WOT. You can buy wideband o2 sensors that'll give accurate readings during WOT and use them for tuning. But, the car will still be in open loop.
#47
#48
It is funny. I was talking about the shifting. How many of you guys have heard, seen, experienced it. Some people have said it before too. Feels slow when it is shifting. Has nothing to do with WOT. You all right it should e the same WOT in the gear but when it shifts it is slower. Like there is some time after shifting before it actually goes. When I reset the ECU after her driving it fixed that problem. Anybody with explaination? I tried just floor it after that and did not help. The reset helped right away.
tg
tg
#49
Originally Posted by trey's wife
For future reference, you don't have to reset the ECU in a case like that. Just take it out and thrash it a little bit and then drive like you normally do and it will adjust quite quickly actually.
Oh and tell the wife to live a little!
Oh and tell the wife to live a little!
I keep telling her but she is how she is I guess.
#50
Originally Posted by tg1234
It is funny. I was talking about the shifting. How many of you guys have heard, seen, experienced it. Some people have said it before too. Feels slow when it is shifting. Has nothing to do with WOT. You all right it should e the same WOT in the gear but when it shifts it is slower. Like there is some time after shifting before it actually goes. When I reset the ECU after her driving it fixed that problem. Anybody with explaination? I tried just floor it after that and did not help. The reset helped right away.
tg
tg
#51
Originally Posted by silverG2007
When it comes to open vs. closed loop, o2 sensors aren't accurate while cold. They actually have heaters built into them to warm them up to be accurate sooner (to get into closed loop).
Like I said before, at WOT, the car ignores the o2 sensor feeback because the sensors aren't accurate anymore. It does still use MAF readings but ignores fuel trims completely (which is why it's called open loop).
If you log a car during PE mode and WOT, the fuel trims all go to zero.
Like I said before, at WOT, the car ignores the o2 sensor feeback because the sensors aren't accurate anymore. It does still use MAF readings but ignores fuel trims completely (which is why it's called open loop).
If you log a car during PE mode and WOT, the fuel trims all go to zero.
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Originally Posted by LiquidGx
I've toyed around with both OBD I and II cars logging with http://www.technomotive.com/ on the OBD I and Tunerstein for the II car. Under WOT conditions in either car when cold or hot, the O2 reading is flat i.e. a consistant voltage like .89v. When throttle is anything but WOT, the O2 reading fluctuates greatly. Here is a log, you can see for yourself.
but i have never tested a sensor when cold...i thought they dont switch and stays at higher voltage until warmed.
#54
Originally Posted by LiquidGx
I've toyed around with both OBD I and II cars logging with http://www.technomotive.com/ on the OBD I and Tunerstein for the II car. Under WOT conditions in either car when cold or hot, the O2 reading is flat i.e. a consistant voltage like .89v. When throttle is anything but WOT, the O2 reading fluctuates greatly. Here is a log, you can see for yourself.
However at WOT, the o2 sensors are NOT being used for fueling. You can see that by logging your STFT and LTFTs (short term and long term fuel trims). They zero out while in PE mode (which includes WOT).
Also, while the voltage is constant at WOT, the stock o2 sensors are not accurate during WOT. Widebands are.
While logging your o2 sensors, you'll also notice they don't start fluctuating (low to high) until they're warm.
When they're fluctuating..... they're working. That's exactly what they're supposed to do.
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Originally Posted by silverG2007
In "o2 speak" when the voltage bounces back and forth, it's called, "switching."
If the o2's don't do that, you get a DTC that reads "Improper switching bank 1 or 2 sensor 1." That's the front o2 sensor.
If the o2's don't do that, you get a DTC that reads "Improper switching bank 1 or 2 sensor 1." That's the front o2 sensor.
o2 sensors has to be able to switch and switch in a timely matter.
what i used to do is test o2 sensors with propane or carb cleaner to drive it rich or create a vacuum leak to force it lean. if voltage does not drop then it usually would mean it was a faulty sensor in most cases.
#60