Supercharged111
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Not that I'm aware of. It also doesn't support data logging, but tuning software can do both.
How do u adjust the fuel/air mix on a L31 350 5.7l vortec.
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Not that I'm aware of. It also doesn't support data logging, but tuning software can do both.
BlazinBlazer1994
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Just curious, WHY do you want to alter the AFR on your set up?
Supercharged111
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Because it, among a myriad of other things, are completely hamstringing the thing.
Thanks for the info.What’s your objective?
There are some AFR parameters that can be “tuned” to influence the relatively brief operating periods when the ECU is operating in open loop mode.
In closed loop operation, AFR ratio is determined by the narrowband O2 sensors’ feedback.
The L31 was never equipped with a wideband O2 system and I’m not aware that the 0411 ECU can enable wideband operation. I’m sure someone else will speak up if that’s possible
I assume the L31 engine in your Cadillac is still equipped with the O2 sensors. I can’t imagine the installer would’ve eliminated them and run the system open loop.
Please confirm your engine is still equipped with the O2 sensors.
For the record, and to the best of my knowledge, the only way for an individual to tune the 1997 black box ECU is using JET’s Dynamic Spectrum Tuner. A few members here, including myself, have this tool. Otherwise, there may be a third-party such as Blackbear Performance that can do it if you send it to them / exchange it with them.
Yes i have both 02 sensors and catalytic converter.
The engine is running to rich, so i just want to adjust it down a little.
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Its running to rich.
If it’s running too rich, you’ve got a problem. You don’t need an ECU modification.
L31MaxExpress
I'm Awesome
Looking at the air intake alone, the MAF calibration will definitely be out to lunch.
Yes, which would warrant an ECU mod...
...so I was a bit hasty with my earlier reply.
I still wonder whether something is amiss and causing it to run rich: O2 sensor, vacuum leak,...
L31MaxExpress
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It is possible. Leaking fuel pressure regulator or injector o-rings at the metering block are a possibility as well.
I would love to know what he considers rich. Factory tune can easily have the fuel trims +/- 15% and the actual air/fuel ratio still spot on.
When I tune I try to keep my trims in the -5% range. For sake of an example this was pretty darn close to where I want one to run fuel trim wise. When I tune with a wideband in open loop and then re-enable closed loop it tends to do this naturally. The GM settings on the oxygen sensor run a little leaner than stoich about 95% of the time.
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Well, do you have a Check Engine Light, i.e. stored Diagnostic Trouble Codes (DTCs)?
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