New to GM Tuning - 4.3 to 5.7 swap???

[Griff1999]

Hello, I did a 5.7 swap in an '03 Sonoma 4x4. I installed an '02 5.7 with an 0411 ECM. I have a small stumble around 2000-2500rpm. I have used older Holly and Accel EFI systems. How would I watch the fuel map live to know where the stumble is to adjust the fuel at that position in the MAP? Or is that not how EFI Live works? Thanks for the help.

[joecar]

Hi Griff,

What was the donor year/model/vehicle for the 5.7L...?
Did the 0411 PCM come from same vehicle...?
How is MAF plumbed (post pics)...?
Are the front NBO2 sensors being used...?

Log the following pids:
SAE.RPM
SAE.MAF
SAE.MAP
SAE.IAT
SAE.ECT
SAE.LONGFT1 and 2
GM.SPARKADV
GM.KR
GM.HO2S11
GM.HO2S21 (watch where the 2 is)
GM.TP

You might also need the check that all the spark plugs are and injectors firing under load in the rpm range you indicated (easier said than done).

[Supercharged111]

Also post the tune. Did you start with a van PCM? That's the only 411 that came tuned for a 350. Is the engine modified at all?

[1FastBrick]

Also post the tune. Did you start with a van PCM? That's the only 411 that came tuned for a 350. Is the engine modified at all?
Actually, in Mexico the trucks and the suburban you could still get the old L31 5.7L in it... https://forum.efilive.com/showthread.php?28867-Ls1b-l31-5-7l&highlight=Mexico

[Supercharged111]

Actually, in Mexico the trucks and the suburban you could still get the old L31 5.7L in it... https://forum.efilive.com/showthread.php?28867-Ls1b-l31-5-7l&highlight=Mexico

I never realized there were EFILive tunes floating around for those, nice. I'm assuming the OP is using the 512k PCM though.

[1FastBrick]

I never realized there were EFILive tunes floating around for those, nice. I'm assuming the OP is using the 512k PCM though.

Yes, a 411 is a 512K PCM and there are Mexico market based L31 tunes out there for a 512 PCM.

[1FastBrick]

Here is a 2001 L31 from a mexico market truck 23602

[Supercharged111]

Yes, a 411 is a 512K PCM and there are Mexico market based L31 tunes out there for a 512 PCM.

Is there anything special about a 512k Mexico L31? I thought the appeal of the Mexico L31 was the one that came with the 1MB PCM, thus giving a factory starting point to be able to run the later PCM.

[1FastBrick]

Is there anything special about a 512k Mexico L31? I thought the appeal of the Mexico L31 was the one that came with the 1MB PCM, thus giving a factory starting point to be able to run the later PCM.

I can not think of anything specific.