Closed-loop Tuning - E-manage, Vafc, Etc..
#11
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Originally Posted by fperra,Jul 10 2004, 07:07 AM
I've been using the emanage for the last 13 months so I have some experience. During close loop conditions, the factory ecu will compensate for any changes you program into the piggyback to maintain 14.7. If it has to correct too much, you will get CEL lights for short term fuel trim, which will eventually lead to a long term long term fuel trim CEL. With larger injectors, ittook me a while to get it right.
Thanks
#12
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Yes you can. If you have larger injectors, you adjust the closed loop so the factory ecu isn't constantly compensating for the emanage. You know you are there when you stop getting CEL lights for short term fuel trim. For open loop conditions, the settings for the emanage are not compensated for by the factory ecu. Adjust the emanage for an A/F of about 12.5 open loop. Its not too hard to get the closed loop adjustred if you have OBDII software that datalogs.
#13
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I'm not quite understanding how you are tuning for closed-loop. As I'm understanding it, the e-manage will continue to compensate for any changes you have made in closed-loop. How does larger injectors eliminate the ecu from compensating for afr changes?
Also, what size injectors are you using? Now that you say your closed-loop is tuned, what AFR are you running at (average)?
Also, what size injectors are you using? Now that you say your closed-loop is tuned, what AFR are you running at (average)?
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Did some reading on ECG o2 Simulators. Could this be used to help a piggy-back system tune closed-loop?
As I understand it, the o2 sim basically takes tps & rpm signals and used a pre-determine mapping to adjust the amount of fuel. If this is the case, then using a piggy-back would allow us to add/remove fuel without any compensation from the ECU since the emulator has a static map.
Also, for those using the ECG sim, do both stock o2 sensors need to be plugged in to have this work? I'm not using a straight pipe, but I'd like to hook my wbo2 sensor into the stock primary o2 sensor position.
As I understand it, the o2 sim basically takes tps & rpm signals and used a pre-determine mapping to adjust the amount of fuel. If this is the case, then using a piggy-back would allow us to add/remove fuel without any compensation from the ECU since the emulator has a static map.
Also, for those using the ECG sim, do both stock o2 sensors need to be plugged in to have this work? I'm not using a straight pipe, but I'd like to hook my wbo2 sensor into the stock primary o2 sensor position.
#15
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The EGC simulator uses rpm and tops signals to produce a false secondary 02 sensor input. The secondary 02 is used by the PCM to verify the catalytic convertor is operating. You would NOT want to tune by a simulated sensor input.
To use an ECG, you can either leave the secondary 02 installed in the straight pipe, or use a 10ohm 10watt resistor wired to the 02's heater, to keep the light of for a P0141. (secondary 02 heater failure)
The primary 02 is still used by the pcm for closed loop fuel trim adjustments, and needs to remain installed in the exhaust manifold.
There is a wideband 02 sensor on the market (PLX)that is installed in the primary 02 sensor location, that has a narrow band output for the PCM.
To use an ECG, you can either leave the secondary 02 installed in the straight pipe, or use a 10ohm 10watt resistor wired to the 02's heater, to keep the light of for a P0141. (secondary 02 heater failure)
The primary 02 is still used by the pcm for closed loop fuel trim adjustments, and needs to remain installed in the exhaust manifold.
There is a wideband 02 sensor on the market (PLX)that is installed in the primary 02 sensor location, that has a narrow band output for the PCM.
#16
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OK.. I think I was a little confused there. The primary o2 stays in place and closed-loop stays intact because its getting the AFR reading off of the primary. The secondary is only used to verify that cat is working and the emulator is emulating only the fact that the cat is working.
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