leaning out / backfiring

[hpmachine]

I just installed my AEM wideband sensor and i'm fooling with my safcII. I've got the car running pretty well. My a/f ratios are between 11 and 12.5 all the way through the rev range but i've got a couple issues. first of all my car is running rich at idle - like 10-11. i've been told it should be at about 13-14. I can get it to lean out at idle by adjusting accordingly with the afc but then its seems too lean and it won't rev up smooth til about 2000 rpm (after that it's fine). the other thing is when i back off the gas it just totally leans out. like all the way and then it'll just backfire until i get on the gas again. will the decel function on my afc keep it from leaning out so much when i back off the gas??? thanks in advance. oh and thanks to everyone that has helped me get this far

[Blown240sx]

I just installed my AEM wideband sensor and i'm fooling with my safcII. I've got the car running pretty well. My a/f ratios are between 11 and 12.5 all the way through the rev range but i've got a couple issues. first of all my car is running rich at idle - like 10-11. i've been told it should be at about 13-14. I can get it to lean out at idle by adjusting accordingly with the afc but then its seems too lean and it won't rev up smooth til about 2000 rpm (after that it's fine). the other thing is when i back off the gas it just totally leans out. like all the way and then it'll just backfire until i get on the gas again. will the decel function on my afc keep it from leaning out so much when i back off the gas??? thanks in advance. oh and thanks to everyone that has helped me get this far

14.7 is the recommended Idle A/F but its not required. Now under boost you need to be below that.Decel Air does control the car from stumbling but its not because the car is leaning out its actually from losing read air by the MAF that the BOV exspells.Also backfiring is usually a sign of rich conditions and also when you let off the gas rapidly all cars go to lean then richen back up. My buddies RB pegs the Wideband out at 16 when he lets off.

[hpmachine]

As soon as my foot is on the gas my a/f ratio is nice and steady between 10.5-12 and that's all the way into boost as well. I know that's good but when i back off the gas it immeadiately begins backfiring and my a/f ratio pegs to the lean side. you think that's okay? also i never have any problems with stalling and my bov is vented to atmo... i just would like the car to stop backfiring!! also i wish it wasn't burning so much fuel at idle... thanks

[Blown240sx]

Backfire like I said is a sign of a quick rich condition. Also like I said going lean right off throttle is normal. Youll need to mess with the SAFC to lean our your idle. Make sure your Points are set as low as your idle. Id go as low as 700 on your first point.

[hpmachine]

thanks dude

[hpmachine]

i still haven't been able to resolve this backifiring issue. the car is getting really nice afr readings all the way through the rev range but as soon as i back off the gas...... popopppoppopp POP! BANG! and it continues to do this til I'm on the gas again. (or til i throw it into neutral) anyone got any other ideas?

[Blown240sx]

Like loud popping almost like a fire cracker? Is it consistant?

If it is consistant your timing could be retarded. I know there are some anit lag systems that retard timing to cause a lot of unburt fuel to enter the exhuast to spool the turbo up. Thats just something o check but probably not it.

Id sy if its just some pops its normal cause my car will do it. It could be an exhuast leak causing it though cause I know mine pops more now with the dump pipe leaking around the non existant gasket.