Can I get a couple of data points from yal? I'm hunting for the cause of an incessant misfire at idle, and possibly related poor fuel mileage.

I'm wondering if my MAF is under reporting air flow. I changed spark plugs a week ago and most of them looked as if they were running a little lean.

Anyway, the MAF readings I'm getting are (this is at operating temp and between 650-700idle speed) bouncing between 5-6g/s.

Revving in neutral to 2500rpm I saw around 19g/s.

I'm not getting any codes whatsoever and it's revving fine, but the misfire at idle is very noticeable and extremely aggravating.

 

I can double check in a day or two; someone else may be able to sooner.

Are you sure it's not a vacuum leak? Sounds a lot like it.

 

Not positive of anything yet, but I hadn't started down that road yet because I would think it would result in an O2 code.

 

I've never had a vac leak result in an O2 code on the disco,, so I'd check that out before I assumed MAF assuming there are no other MAF associated codes. You can also try some MAF cleaner spray. That's been a game changer for me on a couple vehicles.

 

That's usually the first thing that anyone mentions when dealing with O2 codes relative to out of bound readings. I would think that enough unmetered air to cause a misfire would likewise cause over-fueling and an associated code.

I'll jump down the various rabbit holes in due time, but for the moment I've got definite data right in front of me that I can cross reference with others.
​​​​
​​