ok, so i am swapping an lt1 into another car. just got the thing running, and don't have any radiator fans, so i have yet to get the car into closed-loop.

so, in open-loop, the car is running rich at idle, and seemingly off idle too. so when i mash the throttle, it will bog and backfire thru the intake/maf. i have a cc306, and headers, 1.52 rockers, otherwise stock. as a baseline i used

http://www.bfranker.badz28.com/LT1Ed...ds&cam_306.lt1

as a baseline. i modded it for a different rear end and tires. turned off vats. turned off a lot of a/c egr type trouble codes on the switch list. changed for the 30# svo injectors.

it ran a little worse with the base program. after searching here, i changed most of the "iac target rpm vs. coolant temp" values to 1000 to 875 rpm. i also changed the "closed tps vs. spark advance " at 800 to 26 deg. and 30 deg at 1200. this gave me more vacuum at idle, tho still only about 9 inches.

now it idles, but i can only ease into the gas. does anyone have any ideas on where to begin to clear out this stumble? i use tunercat, so i can flash the hell outa the pcm. i don't need exact values, just a point in the right direction. like, do i need to modify my main spark advance tables to reflect the 30 idle timing i have set? or, even better, is the file specified using a stock maf cal? how do i tell?

p.s. now that i figured out the compare feature in tunercat, it seems that the file i used as baseline is not showing any/many differences between it and the stock lt1 program, other than those i know that i made. so i guess the question becomes, what changes do i make to the program for the cc306 and headers?

 

I'm running 41 advance on closed tps. Same cam..

I'm a fully forged 383 12lb blower motor tho.
I hate that cam in my mortor, but liked it when it was n/a.

Also this is a *BUMP* since i have the same sorta issue.

 

Not enough timing advance can cause bogging/back-firing. I'd try adding 2-4* throughout the lower RPM range and see how that helps.

 

Maybe it's the iac target value, i can't seem to get any control over that. how does one move that value up.

Seems to idle fine about 80-90.. so rich it sets off my detectors in the house.. i'm outside of course.

It does not matter what i do it runs rich, i'm thinking about moving my maf to the presure side.

At this point i can't even drive my 10k motor..

Edit: Ugg silly me since i put on the new 190cc heads i'm of course moving tons more air, i cranked my throttle stop a turn and everything is solid..

First time i've seen 108+ blms at idle.