Just ran my first Datalog. Questions. (Kinda Long)

[Joes95GT]

Then why am I getting a 12.8 lambse but a .96xx kamrf. Wouldn't that mean I'm "supposedly" running 16.6:1, but the kamrf is trying to lean it out. And it is obviously rich, because when I let off at high rpms it does the gurgling backfire deal. Never used to that...

EDIT: kamrf is at .98xx while the lambse is targeting 12.8 in the upper rpms.

Jake

From what I understand, most people don't take the lambse for being very "accurate". I'd pay more attention to the KAMRF and get that dialed in, and then worry about the LAMBSE.

Hopefully Dave and/or Grady will chime in and help. I'm just guessing...

Joe

 

[Rootus]

Then why am I getting a 12.8 lambse but a .96xx kamrf. Wouldn't that mean I'm "supposedly" running 16.6:1, but the kamrf is trying to lean it out. And it is obviously rich, because when I let off at high rpms it does the gurgling backfire deal. Never used to that...

EDIT: kamrf is at .98xx while the lambse is targeting 12.8 in the upper rpms.

Jake

KAMRF & Lambse are not directly related.

Lambse is simply the instantaneous target ratio -- what the EEC wants, not necessarily what it's going to get.

KAMRF is a modifier that the EEC uses to determine what adjustment to the "standard" calculation is necessary to achieve the desired ratio. A KAMRF of .98 simply means that for whatever air/fuel ratio the EEC is targeting right now, it has learned over time that it should subtract 2% from the calculated fuel delivery. It doesn't matter if the currently targeted ratio is over or under stoich. The EEC is making assumptions based on how big you've told it the injectors are, what the MAF should read at certain air flow rates, etc. KAMRF is an error adjustment.

Dave

 

[final5-0]

You guys have the correct basic understanding of what is going on. The Lambse is what the pcm is commanding based upon what the sensors tell it.

If things are lean then the lambse will command something less that 14.7 to 1
to try and obtain the desired perfect ratio.

The KAMRF's are all about 1.0 as being the ultimate goal for the adaptive strategy. If you see your K's are greater than 1 then the pcm is adding fuel and that means that at that point of load, rpm, etc, things are lean.

The above info is about being in CL and making assumption that the maf curve & fuel tables are as they should be.

Later
Grady