Microsquirt base map help
I'm running a micro squirt with aem x wide band and I am trying to learn to make changes, problem is truck is fat , and I am trying to lean it out at idle and not sure where to start on that and ignition tables.
My setup is :
2003/2004 6.0 lq9
Home ported 799 heads
Btr stage 4 cam and springs
Fast lsxr intake and warr 102mm tb
1 bar map
NA setup pump gas
No iac at moment have it turned out and using idle screw at the moment. Probally will change to a efi source module at some point .
Thanks for any help and thanks for having me !!!
The IAC is something you can look at for improving idle. To lean it out, make sure you are in SD, and also look to see if your injectors are hitting the "minimum" pulse width. If you have the min pulse set too high, nothing you do to the VE table will reduce the fuel since the pcm will not spray less than whatever that number is. Once you have control over the minimum amount, then VE settings come in.
You'll find that big cams like to run on the leaner side at idle due to oxygen escaping into the exhaust during idle conditions. All O2's read ONLY oxygen differential between inside and outside the exhaust. The greater the difference the more voltage they make. So fueling is not at all what they are picking up. Armed with that knowledge, you can assume a lot of overlap acts kind of like an exhaust leak, at least at idle.
When RPM increases, air velocity and scavenging make up for this (cancelling it out), and the number should get back to being within 2% of your VE and commanded above about 1400 RPM. So if it is reading lean under throttle, then it's actually lean and needs more fuel.


