i noticed something today. sitting at idle. the a/f ratio swings wildly from 14.9 to 14.0

cool, no biggie. look down at the box 2 mins later, it's sitting at 12.2-11.9. what the hell!?!?!

 

at first start up with my car sometimes it goes as high as 15s on rare occasions it hits16s and starts to kinda bog, then drops to 14.7 and from there its fine, still not sure how to get it steady.
listening..

 

HEY MY AEM WB Is bouncing from 16.5 to 14.9 at idle. I don't know if I have an exhuast leak were my dp and manifold connect but I wouldn't think it would read like this. And when I had it in the bung behind the CAT it stayed steady at 14.7 to 14.9.

 

the cat plays a lot to do with it.

before the cat it is going to bounce around.

mine is bouncing a lot more in the wrong direction

 

Mine bounces around 14.3-15.3 at idle.

PLX-M300

 

maybe i should have specified something.

im looking to more or less stabilize the fuel side at idle.

fuel is not my strong point, timing is

 

so, no one has a clue about the idle a/f ratio, or what section it "might" be in on the hpt stuff?

 

It's in open loop, it's supposed to bounce around. You can't stablize it unless you disable the O2 sensor.

 

Thats correct, in closed loop the pcm uses the narrowband to achieve a 14.7 afr. In doing this it sometimes bounces around as the trims compensate for the conditions at the time.

 

um, yea
not from 14.9 to 12.4.

to people who know cobalts, is idle mixture done through ve, or a hidden table somewhere?

for some odd reason im thinking it's done in the VE side of things.

 

We don't have access to idle airflow tables. Your problem sounds more like incorrect minimum pulse width settings though. Try different numbers in there near the 1ms range and see what happens. I think the correct numbers are on the hptuners forum somewhere.

 

short pulse limit is set at 2.000
min PW is set at 0.094

stock gm stage 2 stuff

 

Thats good for 42 pound injectors, 60s not so much.

 

thats what im running right now

got me, guess i will have to live with it

 

changed one of the tables around a bit, got the idle a/f to stay in the 14 range instead of a random dip into the 11's

seems happier now

 

i know ive woken a old thread i just got my wideband in and at idle ill see 14.5-16.0 . Same during just "normal" driveing but the second i press the pedal it goess 11.5 - 10.9.

and mine is before the cat i got the ZZP 2.5 with the extra bung

 

cool thanks. but no never got in to D&D

 

It's called PE.

 

im kinda new to this reading what i can having people help me tune now that i got the wideband i tune a little safer