808ws6

iTrader: (6)

Sorry if the question sounds redundant or basic, but still new to the tuning scene and would like to know what AFR should I be seeing with my MS4 cammed LS1 in the following conditions:

-IDLE hot/close loop
-Cruising at light throttle
-Cruising moderate throttle
-Cruising WOT

I have an LM-1 wideband and using EFI live. I changed the settings in the LM-1 to the settings suggested by EFI live in Analaog1 and Analog 2 outputs.

TIA

foff667

iTrader: (2)

-could be skewed depending on overlap
-14.7
-12.2-14.7
-12.2-13.2

SSpdDmon

iTrader: (10)

That's how I'd do it.

808ws6

iTrader: (6)

That is what I was thinking. it has 239 duration 649 lift on intake and 609 242 dur on exh, so I was wondering if I am looking at a skewed AFR of 1.7 at idle?

What does PE do and how does it kick in?

Thanks again guys!

Gil

foff667

iTrader: (2)

PE=Power Enrichment ie changing from stoich to richer than stoich commanded afr.

edcmat-l1

iTrader: (10)

Idle A/F will definitely be skewed. Are you seeing 1.7:1, or 17:1?
Thats a good bit of duration. Do you know the LSA? From that you can calculate overlap. THATS the magic number as far as idle tuning.
Also manifold vacuum at idle.

808ws6

iTrader: (6)

Thanks for the PE explanation, always wondered what that was all about

I am seeing a range from 15.3 to 16.7 AFR at idle right now.

I tried enrichening the whole MAIN VE table in 5% increments and seems to slightly bring the numbers down and the LTFT (idle and driving) comes down but it smells really really rich. It also seems to be having a harder time starting when I got to about 20% enrichment over stock VE.

If I follow the AUtoVE process, should this be able to help me out with my AFR?

Thanks everybody for trying to help me out!

SSpdDmon

iTrader: (10)

Well, if you don't want it to smell rich at idle, you'll need to change the closed loop idle settings. Either set up a custom operating system or futz with the PE settings for <1200 RPM's & the TP% PE Enablers so that it idles in open loop. Then, you can lean it out without the fuel trims getting in the way.

808ws6

iTrader: (6)

SSpdDmon,

Thanks for helping me out with this, much appreciated.

So do I change the PE settings in "PE Modifier based on RPM"? If so, what value do I enter in the below 1200 rpm fields?
I've noticed there are no clear cut and dry mininum RPM for closed loop setting I can change.

Once I can get it to stay in open loop at idle, I can change the "Commanded Fuel when in Open Loop" chart to get it to not smell so rich, correct?

Just in case I did not mention it, I am using EFI live.

Many thanks again

808ws6

iTrader: (6)

The LSA is 111.5 deg

Thanks!

SSpdDmon

iTrader: (10)

Your best bet is a custom OS. If you decide to try and make it work as I described above, you need to have closed-loop enabled. You set the PE table for your idle regions at the AFR you want for idle (ie: 800=15.8 & 1200=15.0, which would make 900=15.6). You'll have to set the Commanded Fuel in Open Loop (in the idle regions around operating temps and MAP) similarly. Then, change the PE Enable table so that 0% TP% will turn PE (open-loop) on. I'm assuming with that cam you won't be driving it hard at 1200 rpms. This is still somewhat experimental and I've only heard of a couple people doing this. So, there may be some side effects. But, it'd be worth a try.

Fratsit

iTrader: (1)

Hmmm...very interesting. Maybe I'll try this for sh*ts and giggles.

R/

Frat

RonSS

I know I’m digging up a really old thread but I did this today! I just changed {B3616} - Normal PE Mode enable - to 0% at 0 to 1200 RPM and sure enough I got open loop at idle. True AFR, measured with a 5 gas, went from 13.7 to about 14.3. This is with out changing {B3618} – PE Modifier Based on RPM – or {B3605} – Commanded fuel when in open loop -.

SSpdDmon was right when he suspected there might be side effects. After about 30 seconds it set the DTC P0131 (B1S1 O2 sensor low output) and P0151 (B2S1 O2 sensor low output). After that it goes into OL-Fault and won’t go into CL. I killed the DTC’s (both processing and MIL) it ran about 30 seconds again then set P0137 and P0157. Same codes except for the rear O2’s. Killed those DTC’s (again both processing and MIL).

After all that I have OL below 1200 RPM and it pops right into CL at anything above 1200 RPM until you stand on it hard enough for “real” PE. Because I have not changed any values in any of the PE tables as far as AFR I don’t see any reason that “real” PE should not work as before.

I’m a little surprised I did not see DTC’s for slow response or insufficient activity on the O2 sensors after letting it idle for about 15 min. Maybe the PCM only checks that at speed? I’m hoping that I don’t have to kill anymore O2 DTC’s so if down the road I do have one go bad I’ll get a MIL. I’ll have to drive it some more to see I guess. Drove it about 2 hours today, some freeway some stop and go, and it seemed fine to me. From the drivers seat I can’t feel the transition from OL to CL when I take off from a stop. Time will tell………

Vehicle: 02 C5 Coupe Cam: 224-224 on 114’s OS: 12221588