383 w/Hot Cam tuning problems (tune/log inside)

[Sherk]

Hey guys,

I can't figure out this tuning thing for the life of me. Can someone please have a look at my tune/log?

She's a 383/Hot Cam running off the 411 ('01 Express van base) with stock Vortec injection.

She starts up just fine and sits there idling (RPM does jump some though), but according to the wideband O2 sensor that I installed today, she's on the rich side of things. Also, I bumped up my idle speed, but I still get random backfiring (misfires?). The truck isn't driveable in the condition it's it, I can't rev it over about 1500 or so RPM. At that point, however much throttle I have in it, it bogs... I don't know if that's the correct term for what it does, it acts like it wants to stall and RPM falls.

[Goldfinger911]

Have you done an RAFIG and AutoEV tuning? Your VE map looks very close to stock. Also, what kind of injectors are you running? Your IFR table is flatlined at 2.9141 grams ? Is starting a problem? Your VE While Cranking is all zeros. You might want to start with a stock VEwC map then when AutoVE is done, calculate a proper one.

[Sherk]

Starting isn't an issue at all. Truck cranks and immediately fires...

The injectors are the upgraded MPFI spider, but still stock style injectors (so I didn't change much of the tune, cyl volume and some other minor stuff).

I haven't done a RAFIG... I'm looking into that now. I'm 100% new on this stuff, and lost. Will RAFIG help me reach past 1500 rpm or so?

[mikeyayell]

Is your MAF still plugged in?

[Sherk]

It's unplugged currently, I should have everything set up for an SD tune.

[Goldfinger911]

RAFIG is a tuning process for desired airflow at idle only. AutoVE is tuning the entire operating range. Have you done AUtoVE according to the FAQ that EFILive provided?

http://download2.efilive.com/Tutoria...20Tutorial.pdf

Looking at your VE map, it doesnt look like it.

[Sherk]

Well, I can't do much AutoVE-wise, as the truck isn't driveable (I did make some adjustments to the VE table myself to try and give it less fuel down low, which it seemed to like). I still can't get it to rev over about 1600 rpm now...

It will sit there and idle, when it's revved up it will bog/stumble down and go under my set idle, and backfire. Anywhere between 800-1400 or so rpm and it runs decent. Outside of that, it just won't go there.

I don't know how to proceed with the AutoVE process in the current state, is what I'm trying to get at...

[hquick]

Sherk...have you got a wideband connected?

[Goldfinger911]

Well, if you plan on sticking with this tune, you are probably going to have to first set your Injector Flow Rate properly first. Then, run the tuning tool while logging and watch what regions of the VE map are being touched when it bogs and runs poorly. If it is rich, remove fuel. If it is lean, add fuel. Get it driveable... then start the AutoVE process. You are going to need a wideband installed and the 5v linear output wires to your FlashScan device so you can properly calculate the BEN factor.

[Sherk]

Yep, she's got an LC-1 connected, and working properly. I've been logging all that I can for the short periods that I run it.

Here's a log (I know it's not the greatest) of some of the later stuff I was messing with. It gets lean with higher manifold pressure and doesn't really give any clues as to why it won't rev past 1600 rpm.

Any ideas?

Also, I left the IFR table the way it was because they're stock injectors. School me as to what needs to be changed, please. Most of the stuff I understand, however some of it is completely new to me, like this.

I appreciate the help guys.