Ignition timing issue
08-15-2004, 05:59 PM
#1
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Ignition timing issue
Here's what timing used to be like, though I dont know if any timing was pulled back.. This was before a ran a voltage clamp on the map sensor
<img src="http://members.shaw.ca/dannykso/timing003.jpg">
And now or recently with a voltage clamp:
<img src="http://members.shaw.ca/dannykso/diode-timing.jpg">
Then I was told to try compensating by changing the adaptation values..
<img src="http://members.shaw.ca/dannykso/pulledback.JPG">
So I thought the voltage clamp was the problem, so i removed it, but timing still wasnt back to the way it was. The first log was done back in March, and these two were done a couple of days ago. So there's probably a temperature difference. I searched the archives and Audi2ptzero suggested to log knock voltages block 026, rather than timing retard (020). So whats an acceptable voltage range for knock sensor? Also, in the fuel trims i saw a maximum of 1.6% in 2nd field. Which is ok right? Is block 031 02 voltage, or already lamda values?; I saw a lowest of 0.68 at around 5000rpm in that block. Thanks
<img src="http://members.shaw.ca/dannykso/timing003.jpg">
And now or recently with a voltage clamp:
<img src="http://members.shaw.ca/dannykso/diode-timing.jpg">
Then I was told to try compensating by changing the adaptation values..
<img src="http://members.shaw.ca/dannykso/pulledback.JPG">
So I thought the voltage clamp was the problem, so i removed it, but timing still wasnt back to the way it was. The first log was done back in March, and these two were done a couple of days ago. So there's probably a temperature difference. I searched the archives and Audi2ptzero suggested to log knock voltages block 026, rather than timing retard (020). So whats an acceptable voltage range for knock sensor? Also, in the fuel trims i saw a maximum of 1.6% in 2nd field. Which is ok right? Is block 031 02 voltage, or already lamda values?; I saw a lowest of 0.68 at around 5000rpm in that block. Thanks
08-15-2004, 10:20 PM
#2
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On block 026 you want to keep it below 20 but the max reading
is 29's which is where the car will start to ping. On block 026 you will notice that cylinder #2 will be the highest and that is the one you want to watch the most.
For the 2001 and newer cars your 02 sensor reads in lamda. This means that values lower then .86 will be richer and higher values will be leaner. SO this means your .68 is way too rich.
Now when you say fuel trim, do you mean block 032? If so it means your fuel trim is on the lean side for part throttle(2nd reading) and first reading is for idle.
For the 2001 and newer cars your 02 sensor reads in lamda. This means that values lower then .86 will be richer and higher values will be leaner. SO this means your .68 is way too rich.
Now when you say fuel trim, do you mean block 032? If so it means your fuel trim is on the lean side for part throttle(2nd reading) and first reading is for idle.
08-16-2004, 08:13 PM
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Hm... I removed the mbc or basically returned to stock, and timing was back..
I just realized something though, I'm running a 4.3v diode on the map sensor now, and block 115 shows a maximum of .74bar which equates to 11psi, and according to this table..I have a 2BAR map sensor?!
<img src="http://www.nebulight.com/misc/map/2BARvs3BAR_MAP.gif">
<img src="http://www.nebulight.com/misc/map/2BARvs3BAR_MAP.gif">
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08-17-2004, 09:45 AM
#8
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Audi2ptzero: Do B5s have this map sensor? It doesnt look like its made by Bosch
<center><img src="http://members.shaw.ca/dannykso/map%20sensor.JPG"></center><p>
