5.3 with LS6 intake/injectors and COS3 2bar MAFless

[blindawg]

Mafless, and a 2 bar map sensor for the turbo that will be going on it once I get the kinks worked out.

It's a t56 manual, and nothing is from the colorado. It was a 4 cyl. Before I swapped the 5.3 in. For what it's worth, I put an LS9 cam in it.

Thanks,
Branden

[ProperTuningOG]

Well there is your problem....... You are going from pig rig to lean with the 5.3 VE table and LS9 cam. You forgot to mention that little diddy.

You need to tune the VE and go from there.

What MAP are you using?

[blindawg]

I understand I need to do some adjustments with the VE table because of the cam, but I can't do that correctly without the correct IFR for my injectors, right?

Also, it runs petty decent with those truck values in the IFR table. So I wouldn't think the VE is too far off. Am I wrong in thinking this? My profile thing may say "senior member", but I'm nowhere close to being that knolagable. Lol.

Thanks,
Branden

[blindawg]

12615136 GM part number for the 2bar MAP I'm using.

[joecar]

North East Kansas.

I need to verify fuel pressure, I was going to do that when I did the logs. Looking like that won't be until tomorrow morning.

No, it's not vacuum ref. It's a returnless, factory car fuel system. If anything I would say my fuel pump is weak because it had a LOT of miles on it, but it runs decent with the truck values so how could that be the problem? (Just thinking out loud.)

Thanks for the help,
Branden

For un-referenced (returnless) the IFR has to be sloped (same as the LS6 B4001 table).

[joecar]

MAP-referenced FPR: IFR table is flat (same value in all cells since MAP-referenced FPR keeps constant pressure across injector).

un-referenced FPR: IFR table is sloped (slope is squareroot of pressure across injector as VAC (BARO - MAP) increases).

[blindawg]

I understand all that. But where I'm at a loss is why does it run BETTER with the flat IFR table filled with the truck values, than it does with the sloped LS6 values?

[blindawg]

Do I just need to put the LS6 values in and adjust the VE? Is it THAT far off? If so, is using the truck values (which is lower than even the smallest LS6 value) somehow making up for the VE being off?

Thanks,
Branden

[ProperTuningOG]

The LS9 cam is way different than the LM7 cam. Change the injectors values and tune the VE.

[joecar]

+1

compare the cam specs between the LS9 cam and the LM7 cam...