5.3 swap with Z06 cam and delphi injectors running lean on idle no matter what

[Amille28]

I've been slowly trying to learn how to tune the idle on my Porsche 996 5.3 swap with a z06 cam. I have 2003 flex fuel delphi injectors from a suburban 5.3.

I keep leaning out my virtual VE in the e38 computer but i get a LTFT of about -17 to -19 every time in the idle areas. It just won't lean out. I'm going for a 650 rpm idle and tried increasing base idle airflow. I am not running a MAF and trying to tune the SD.

idletune1.hpt

idleflux.hpl

[5FDP]

Maybe upgrade to the 2 bar OS so you can get "regular" VE tables again because you aren't running a MAF.

Are you running a seperate IAT sensor? Just asking because during that whole log the temp never moved from 68 degree's.

Do you have the layout of how you are adjusting the VVE, because it seems whatever you are doing now is creating havoc on the table when you make adjustments. A wideband would be your friend here.

[Amille28]

Thanks for the help. I have upgraded to the 2 bar OS as you suggested. I followed instructions but now my VE tables are all zeroed out. Can I copy in my old Virtual Volumetric Efficiency numbers to get a starting point. My method was to use LTFT and copy them into the Virtual volumetric efficiency table - flash - drive- then try to get it closer. I got to a point where i just could not lean out the idle any more and was getting -17 to -20 LTFTs.

Should I be running a separate IAT sensor? The whole reason i ditched the MAF is because of space on getting the 996 decklid to close.

[5FDP]

I wouldn't use your old VVE table, it's way too messed up to even want to use that.

I would find a stock VVE table for a 5.3 and stick it in there. Your computer says it's from a 6.2 so you wouldn't want to start with that because it's a different motor.

I think you'd find it easier to use a lambda/AFR error to dial this engine in, you need a wideband anyway at this point. It's not worth the risk to not run one.

If you deleted the MAF sensor but didn't run a seperate IAT sensor, you need to run one. The computer needs to know air temp to make correct calculations.

[schpenxel]

Can put the IAT on the intake, passenger side, right after the TB, but you DO HAVE TO HAVE ONE.

Yeah that original VVE table looks pretty rough. I'd start with the (or at least "a") stock one, you'll have to do some copying/pasting into Excel to flip the x/y axis around to make it fit into the new VE table, but that isn't bad to do

Your IAT is exactly 68* the entire log. Do you have a sensor on it or have you tricked it somehow?

Your current VVE table looks really, really bad. Stop blindly copying/pasting. A VE value near 0 beside one of 3000+ simply can't be right.