AFR Issue at Idle

[SloLife]

So I have been fighting an issue since I recently purchased my car. The AFR's at idle are around 14.5-15.5, they seem to jump around quite a bit. The thing that scares me is it will jump to 16 and stay there for awhile. Initially I was thinking vacuum leak. So I have started looking for leaks and haven't been able to turn up much. As a side note, the car will rev up to 1800-2000 rpm's during enrichment, but sometimes will take 5 minutes+ for the idle to come back down to 900 or so. Could this be an issue with IACV? I'm just lost at this point.

I am running a Power Fc with an AFX wideband if that makes any difference.

[steve shadows]

Sending you a private message I think I can probably help you with this right away.

In the meantime I would make sure your fuel system hardware is up to par, replace your fuel filter, and make sure your fuel pump is in good shape. You can check this easily with a t-d off line on the fuel return line and a fluid pressure gauge.

[inopsey]

So I have been fighting an issue since I recently purchased my car. The AFR's at idle are around 14.5-15.5, they seem to jump around quite a bit. The thing that scares me is it will jump to 16 and stay there for awhile. Initially I was thinking vacuum leak. So I have started looking for leaks and haven't been able to turn up much. As a side note, the car will rev up to 1800-2000 rpm's during enrichment, but sometimes will take 5 minutes+ for the idle to come back down to 900 or so. Could this be an issue with IACV? I'm just lost at this point.

I am running a Power Fc with an AFX wideband if that makes any difference.

16 afr is fine at idle and wont damage anything. what is the voltage on your tps doing when this happens (can be read off the pfc commander) any vacuum leaks?

[Livinstrong]

I wouldn't be overly worried about that AFR at idle, your engine is under particularly low load and doesn't need a perfect stoich mix. My SR idles from anywhere from 13.7-15 and varies