Problems leaning out idle
 

hey,
I can't seem to lean out my idle, it's stays rich at about 11.5:1. I can get it to about 12.8:1 if I set the primary lag to -0.22, but I have stock 550 primarys! On my INJ maps I have lowered idle to .5ms, but when "monitering" with the datalogit, it shows 2.5ms, no matter what I put in the maps. When I set the primary lag to -0.22, it will lower to about 2.2ms. I have the O2 feedback and Idle-Ign controls off (I have no ISC). I have even tried taking out 50% fuel at 1000 rpm's (setting 3 on the datalogit) and still won't change from 2.5ms. Is there something I'm missing?

You should be able to unless you have a leaking injector or injector seal.

That's exactly what I was thinking.... However, wouldn't I be able to lower the injector millisecond on time? By using the datalogit monitor feature, the INJ Fr Pr won't change from about 2.5ms even by changing the INJ map, the only way I can lower it is by changing the primary lag. It seems as though I don't have control of the injectors during idle. If I had a leaking injector, the on time would go down but the AFR would stay rich.... correct? Thanks

The PFC only allows a certain minimum idle ms for primaries. That is why people with 850 or larger primaries have to use negative lag to lean out idle.

yea, the minimum I can set it to is .5ms. I was thinking.... What if you don't have the O2 senor plugged in? I have my wideband in the stock O2 bung (not permanent, just for tuning). I know for a stock car, if you lose input from the O2 sensor, the PCM will command a rich condition. I know the PFC doesn't care whether or not you use the O2 for closed loop operation, but maybe it still needs to see that input? What do you think?

But you said the O2 control was off, then it is off!

Yea, the O2 control is off as a feedback to CONTROL fuel. What I meant was that it may need to see the O2 sensor connected and producing a voltage, not neccessarily using it as method of controling fuel but verifying fuel. Is it possible that the PFC will not let you control fuel if it cannot verify the changes made to the map, kind of like how fault codes are generated on a stock PCM.

I just wanted to see how many of you guys have control over your idle fuel mixture. If you do, what AFR's do you have it at?

-0.17 lag dropped the "floor" enough to allow me a 14.7:1 idle with stock injectors.

I'm not sure why you're still that fat with -0.22.

Thanks for your reply. I've noticed that with the headlights on, my idle will lean out to about 12.8:1, but with no electrical load it will go to about 11.8:1. Question: with your datalogit, what INJ Fr Pri ms are seeing while "monitoring"? No matter what changed I make, it will stay at about 2.5 ms (except when I use a negative lag, then it will go down to 2.3). Thanks