Fuel maps don't line up?
Mar 5, 2010, 06:08 PM
#61
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This does sound alot easier then changing everything around to accomodate the new maf scaling. The only thing I am wondering is why I still cant get my afrs to a suitable level in that one rpm range. My theory is even if I bought a rr fpr I would still have the same issue since the ecu would just compensate for the extra fuel and think it needs leaned out to bring it back to its target afr.
Right now, you're assuming that the AFRMAP directly correlates to your fuel table, this may not be true.
It was not true in my case, because lean spool was changing the AFRMAP value. There may be something similar going on for you too.
Also keep in mind you're only getting computer correction in closed loop, and you'll see that as your O2 short term fuel trim (STFT) either pulling or adding fuel. Above a certain load (I don't know what) you're going to switch to open loop where the computer stops trying to "fix" the fuel and just does what it's told based on these tables.
Mar 5, 2010, 06:42 PM
#62
I would still suggest setting a flat fuel table where every cell has the same value. Set it a little on the rich side. Briefly do some light driving and log. If there are no other variables in play your AFRMAP should equal whatever you have those cells set to.
Right now, you're assuming that the AFRMAP directly correlates to your fuel table, this may not be true.
It was not true in my case, because lean spool was changing the AFRMAP value. There may be something similar going on for you too.
Also keep in mind you're only getting computer correction in closed loop, and you'll see that as your O2 short term fuel trim (STFT) either pulling or adding fuel. Above a certain load (I don't know what) you're going to switch to open loop where the computer stops trying to "fix" the fuel and just does what it's told based on these tables.
Right now, you're assuming that the AFRMAP directly correlates to your fuel table, this may not be true.
It was not true in my case, because lean spool was changing the AFRMAP value. There may be something similar going on for you too.
Also keep in mind you're only getting computer correction in closed loop, and you'll see that as your O2 short term fuel trim (STFT) either pulling or adding fuel. Above a certain load (I don't know what) you're going to switch to open loop where the computer stops trying to "fix" the fuel and just does what it's told based on these tables.
Mar 7, 2022, 10:26 AM
#63
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Yes true. I have only been looking at log sections that are in open loop. I have determined for sure that its accessing some higher value. I rescaled my fuel table to 210 and flatened it out and have been able to stabilize my afrs where before they were kinda all over, but I still have the lean issue for some reason. I might get a rising rate fpr and see if this helps. Other than that issue that still persists everything else is starting to come together nicely. I tried to use accell enrich to help in that rpm range until I discovered that table is only for the tip in throttle. I found yesterday that adjusting all the values beck up to a flat 10.0 in the table ad no effect on my actual afrs confirming the ecu does not recognise anything below 10.01.
My AFRMap value is flatlining at 9.1 and isn't in line with my Fuel Maps (at around 5000rpm). The WBO2 shows the car leaning from this point onwards. Attached a log file
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