How do u adjust the fuel/air mix on a L31 350 5.7l vortec.
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CumminsFever
I'm Awesome
Do you know what ecm (computer) was used? What I'm getting at is, it will need tuning to make adjustments, and it may be helpful to know what ecm was used. Maybe you know what vehicle the engine came out of?
Yes.
The motor , all the electronic and ecm is from a chevrolet express van 1997.
Okey so i need to go in with my computer then..
I have and older laptop and
”AutoCom” software, wonder if that would work with this system.
But with that said it does not have any ”adjustment screws” on the tbi ”carb”? ( dont know the names in english sorry)
To clarify im not to stupid.
just bad at english and im not looking at the engine rigth now as im in my bed just thinking about this haha
To clarify im not to stupid.
just bad at english and im not looking at the engine rigth now as im in my bed just thinking about this haha
Cool caddy!
1997 /should/ have the mpfi “spider injection”.
Here is a picture of my vortec for reference. The aluminum piece on top of the intake is just a throttle body. The fuel injectors are inside the intake plenum. The rectangle shaped electrical plug behind the throttle body, is the harness for all the injectors or poppets if they haven’t been upgraded.
Just another picture so you don’t have to take yours apart.
The vortecs EFI are managed by the “black box” ecm. A common upgrade is exchanging with the 0411 ecm. I don’t remember the specifics but some came out of express vans so you might have that already.
The black box requires much older software that doesn’t have much support to tune. The 0411 can be tuned by most anybody with the popular tuning software.
1997 /should/ have the mpfi “spider injection”.
You must be registered for see images attach
Here is a picture of my vortec for reference. The aluminum piece on top of the intake is just a throttle body. The fuel injectors are inside the intake plenum. The rectangle shaped electrical plug behind the throttle body, is the harness for all the injectors or poppets if they haven’t been upgraded.
You must be registered for see images attach
Just another picture so you don’t have to take yours apart.
The vortecs EFI are managed by the “black box” ecm. A common upgrade is exchanging with the 0411 ecm. I don’t remember the specifics but some came out of express vans so you might have that already.
The black box requires much older software that doesn’t have much support to tune. The 0411 can be tuned by most anybody with the popular tuning software.
@Orpedcrow
Hello! Thanks for the pics! Really helpful!
How do i now if its the 0411 ecm?
Is there any type of marking on the box?
I have a ”obd output” to connect to the computer/ ecm / ecu
Hello! Thanks for the pics! Really helpful!
How do i now if its the 0411 ecm?
Is there any type of marking on the box?
I have a ”obd output” to connect to the computer/ ecm / ecu
yes, the 0411 gets its name from the last 4 digits of its service number! And the black box is just a black-box
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
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.
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Supercharged111
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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.
Pretty sure Blackbear can only do 98+. 411 swap is the best option here. Being a swap the engine can simply identify as an 01-02 Express van engine if needed for emissions purposes.
Does the 0411 support wideband operation?
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