Hopefully the experts can give me an easy answer here.

I had the wideband hooked up again this week, I was watching my AFR, it goes right to 14.7 everywhere until I hit PE/AE, and at idle. At idle it is showing in the 12.8-13.1 range, and fluctuates a little bit. Is there a way to modify what AFR the computer is hunting for at idle, or to make it go to open-loop at idle, but leave it closed loop the rest of the time? I imagine the overlap diffrence between my cam and the stocker, is causing the diffrence, as the stock NB *thinks* its at 14.7, when it really isn't. Any ideas are welcome.

--John

 

i added cam 11/2004. idled at 850-900 rpms at 14.5 to 14.9/1(toggle). this spring i removed the tamper proof seal and manually dropped the idle to below commanded 725 and it worked well in that the iac now regulates it to 725 rpms with some minimal surging 600 to 750 rpms. issue developed in that now the WB showed a rich 12.5 to 13.5/1 when idleing for a few minutes(Mc'D's drive thru) at 200F coolant temp. the CE light came on? i will pull code this weekend but i think it was related to prolonged idle. has not happened since but had no reason to idle so long.

is it possible i am seeing the same deal as Dewey?

overlap rearing its ugly head? ECU dumping in fuel as NB seeing effects of cam? was thinking same thought of running OL either at idle only if there was some way. otherwise when air temps stabilize here run a tune that is "summer".