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| Forum name | Turbo/Nitrous Tech |
| Topic subject | SAFC, A/F readings, Adjustment, what the heck! |
| Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=10322 |
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10322, SAFC, A/F readings, Adjustment, what the heck! Posted by jamesman, Oct-01-01 06:22 AM hey i was wondering. If i adjust my SAFC say richer, my A/F gauge shows that the ECU still compensates and makes it the correct A/f mixture. So i was wondering if it is actually doing something. like when i change the AFC setting is the car actually compensating for the new richer setting. If this is the case, tuning the AFC with a voltmeter would be useless, cause the ECU will always compensate to bring the mixture back to stoich and maintain that proper ratio. I was reading the tuning of the afc section on the main board, and i was like huh, because if i richen my afc the ECU appears to just correct the A/F by itself Negating the reading on my voltmeter. say i richen it 10% it will get rich and show rich on the volt meter for like 5 seconds, but then the ECU compensates and brings the A/f ratio back to stoich and then it begins to fluctuate back and forth with the same upper voltage limit as before. so is tuning with the A/F meter for WOT only, cause then how would you tune fro the LO-throttle settings on the AFC? | |
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10323, RE: SAFC, A/F readings, Adjustment, what the heck! Posted by Corbin, Oct-01-01 07:12 AM I wrote a real long post about "fuel trim" on a datalogger thread a few days ago. Reading that will reinforce what you've been noticing with your tuning. The AFC is really only good for 2 things. One is adjusting for much larger injectors. If your injectors are so big that the ECU can't compensate for all the extra fuel, you use the AFC to trick the ECU into injecting alot less fuel. This will bring the amount of fuel being injected back down to the level where the ECU can adjust lean/rich as it needs to. The other thing that an AFC can do is lean things out under WOT. Under WOT, the ECU stops listening to the O2 sensor (and adjusting lean/rich in real time) and just injects how much fuel it thinks will work based on intake temp, manifold pressure, etc. The AFC can be used to adjust the manifold pressure sensor output and trick the ECU into injecting less fuel. So if you have a stock fuel system (injectors, FPR) then the low throttle settings are pretty meaningless. | |
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10324, RE: SAFC, A/F readings, Adjustment, what the heck! Posted by Kory, Oct-01-01 08:25 AM yeah can u tell me why S-AFCs dont work for 96es? i get error code 12 i think map voltage sensor and cant figure it out. it's hooked up correctly for sure, and neither adel, armond, murix or ray can figure it out. sux ass for me | |
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10325, RE: SAFC, A/F readings, Adjustment, what the heck! Posted by Michael_97RS, Oct-01-01 08:32 AM I've had a CE light ever since I installed mine on my '97... | |
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10326, RE: SAFC, A/F readings, Adjustment, what the heck! Posted by koolade9, Oct-01-01 10:01 AM >I've had a CE light ever | |
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10327, RE: SAFC, A/F readings, Adjustment, what the heck! Posted by Michael_97RS, Oct-01-01 10:41 AM Did it without my A/F Meter plugged in... So I have some things to check now... | |
