LM-1 and A/F questions
LM-1 and A/F questions Got my LM-1 and RPM convertor installed and have logged several WOT runs as well as highway/city cruising. Everything looks pretty good to me. AFR tries to stay at 14.7 cruising, but it does swing up and down some. It will swing up and down from around 15.3 to 14.2 roughly. Never having done this, I'm not really sure what this log SHOULD look like. I have searched trying to find som .log files to compare to mine on here, but I havent found any. Does anyone have something I can look at to compare mine to?
That is pretty much normal. You will have some variances in the AFR due to transitions. Once you use the average and start to get things dialed in more, you will still see some of the variances, but not as bad.
The AFR will swing up and down like that when you're in closed loop operation (cruise, idle, etc.). The reason being is the PCM is reading the feedback from the stock O2 sensors as it slightly increases and decreases fueling with the short term fuel trims. If the PCM sees a trend that shows the average AFR higher or lower than a 14.63:1 AFR, it will add or subtract fuel with the long term fuel trims to compensate. When you're in open loop (cold start, WOT, etc.), fueling should be fairly constant since the PCM can't learn here. So, what it commands is what you should see (assuming your tune is accurate). Don't forget on cold starts, the AIR pump will scew your readings lean. So, don't freak out. For more info on this, you should read the stickies on how to tune. There's a lot of valuable information about our PCMs in there...even if you're not tuning (yet). 
