AFR problem! Help!

[1fastgto]

I have been searching for about a week and dont know what else to try, I have a 2002 Camaro, moded with Trickflow 215cc heads CNC'd, small baby almost stock cam, FAST 90 and 90mm nick williams TB, KOOKs 1 3/4 LT's with cats, 3 inch all the way out. I have stock injectors 28# I have 62lbs of presure at the rails with a BBK boost a pump. I scaled the injectors to match the presure. Also have level 5 RPM Automatic, with stealth yank 3200 stall and a 3.42 rear.

Heres my problem, no matter what I do my AFR (watching LM-1) never goes above 14.4, when your cruising at 50 and you let off the gas it should go lean right? mine never goes above 14.4 and then vise versa if I get back on the gas it may go to 14.0 while I am accelerating unless I get it into PE which then makes it 12.5-13.0. I cant get 200 miles out of a tank of gas! I should be able too! It looks to me like DFCO never kicks in and leans out the AFR when I am off the Throttle and continues to dump fuel. and on top of that while I am acccelerating light load normaly shouldnt I get at least into the 13.5 range? My LTFT right now are between 0 and 3.9 while on the gas and -8.6 when off or ideling. Any help or direction would be great! heres my tune and my last log.

[ScarabEpic22]

Need to AutoVE for sure to get your fueling in line, then get the spark setup once you get the VE table dialed in. Just by you saying 0-3.9% LTFTs means you need to AutoVE.

Light load will be stoich (14.7) unless you're running getting into PE. For DFCO, I would try and set the enablers to come on sooner, maybe compare your settings to a stock 02 Camaro.

[Tordne]

Looks like the DFCO enabler for MAP is too low for your cam profile. As you are not running an EFILive COS and using Open Loop fuel control you will be commanding stoich whenever you are not in PE mode.

[WeathermanShawn]

I assume you are running a MAF Tune, as I see B0120 is set to 400 Rpms?

As far as DFCO, at first glance it simply appears that you are not reaching a low enough MAP to engage it B3320 (18 MAP). Maybe you did and I just missed it. If you raised it to a higher MAP, you should hit it.

Even with stock injectors, many cammed cars (including mine) run rich on off-throttle positions. I did a lot of things with injector minimum pulse width etc, but settled on DFCO being the best tool to manage it.

Other than your Injectors looking like they are near their max..(not contributing to your current problem), I would say DFCO MAP is too low, and running MAF only (B0120) perhaps your MAF Calibration Table needs some work (B5001).

[z28ls1818]

arent 02 injectors 26lbers? 98s were 28?

[Tordne]

It's the other way around I think.

[z28ls1818]

It's the other way around I think.

no. im positive about this. i think its posted in stickies on ls1tech.com

[mr.prick]

arent 02 injectors 26lbers? 98s were 28?
They both are 28lb @ 4BAR.
According to Bosch the '02 injectors (0280155931) are 24.74lb @ 3BAR
http://apps.bosch.com.au/motorsport/downloads/fuelinjectors.pdf

[Tordne]

The early LS1s had the LS1 intake manifold which was fitted with 236lb injectors. Can't recall what year they changed to the LS6 intake and the 28lb injectors (definitely before 2002 though).

[mr.prick]

'98=28lb
'99-'00=26lb :nixweiss:
'01-'02=28lb

[z28ls1818]

They both are 28lb @ 4BAR.
According to Bosch the '02 injectors (0280155931) are 24.74lb @ 3BAR
http://apps.bosch.com.au/motorsport/downloads/fuelinjectors.pdf

you sure?
i can swear guys on ls1 sell 99-02s as 26lbers. 98s are for sure 28s. ill have to look into it.

[mr.prick]

you sure?
i can swear guys on ls1 sell 99-02s as 26lbers. 98s are for sure 28s. ill have to look into it.

This is what I have always heard, you can do the math for the '01-'02s
from the .pdf or look at a stock '01-'02 .bin if you don't believe me.


OP, check the calibration/settings for your WBO2 & connect it to Flashscan.
Lean WOT areas probably just need some adjustment.

[joecar]

01-02 F-car has 28.8 lb/hr @ 58 psi, various sources agree on this (see ls1tech.com).

Edit: added @ psi

[gmperformancecentre]

i changed i few things in your tune
give this a try and see it's help's

[1fastgto]

Thanks guys!!! Thanks for all the input, gmperformancecentre I will try the tune today and let you know, I am new to this detailed level of tuning. I want to auto VE but havent got that far yet. I dont have the LM-1 hooked into the efi live yet, all I can do is monitor the AFR right now. As for the injectors they are 12561462 stock, I am almost positive they flow at 28.6 at 58PSI I have done alot of research about them, because you have to start there. Will let you know how the changes go! Thanks!

[hog]

'98=28lb
'99-'00=26lb :nixweiss:
'01-'02=28lb
This is correct. I remember that when the LS1's were relativley new that the dry nirous kits would allow for slightly larger nitrous hits in the 1998 F-cars compared to the 99-00 cars due to the 98 LS1 having larger injectors.

peace
Hog