Big log & probably dumb questions about it!

[dermotw]

Hi,

Various people have explained stuff to me before so I'm hoping someone will for these!

Here is a log of my partially tuned car, the first time I drove it with all the "tuning settings" off and it just as it should be for normal driving (lol). I have a bunch of silly questions:

1/ at around 2 min in, I start it up and let it warmup-idle, & you see that as it warms up the idle starts to swing, and the spark control manages it, kind of, then when the closed loop starts up, it goes back to steady idle. But WHY does it swing? I played with various things to stop it, but the basic behaviour is still there. Look at 1m zoom, around 2:30 it starts.

2/ after that I drive around etc, then I cruise at light throttle for a big section, at that time (14 mins in or so onwards) you can see the 02's are cycling at around once or at most twice a second. Isn't that a bit slow? Also you can clearly see the fueling swinging +/- following them, which I suppose I would expect? I've never looked at a standard car so I don't know what to expect!

3/ Then finally right at the end I goto idle again, then the 02's are only switching perhaps every 2s or so, much slower. I'd expect they are slower, there's just less gas flowing, but is that slow normal?

4/ And one more, when I'm just cruising along, both the idle cracker and follower are 'open', i.e. in use, is THAT normal?

All comments about my questions or anything else anyone sees are gratefully received..

kr D.

[dermotw]

Huh, answered part of it myself I suspect, I bumped into some other's general logs, & their 02 switching speeds seem similar roughly to mine, so perhaps that I can forget at least!

-D