What can you make of this?
My lterm c-counts is all over the place. It wanders between 150 to 118.
Up and down ( se log ).
And its only on idle rpm. If i apply throttle and rais the rpm to 1200, the 02 readings is more solid.
Its like the 02 is "oscillating" and the ECM is always 1 step behind. When the 02 reads "lean" the ECM starts to compensate, then the 02 shows "rich" all of the sudden and the ECM doenst follow fast enough? Just a theory. What do you think?
I burned my old ac delco 02, and now I use a 3 wire bosh unit. Can the bosh unit be the culprint?
Thanks for looking.

Car is a 1991 6spd vette
8D code

 

I thought there was a problem before too but its normal
https://www.thirdgen.org/forums/tbi/...o2-sensor.html

Heard it from two different sources

 

Yeah, I now about the 02 swingpoints. But this is something else. This occure over a longer time.

Cheers

 

I manged to tune the idle a bit more. Right now its somewhat stabel around 124 BLM. But sometimes the BLM get crazy and climb to 140 for no obvious reason. Then back down again and settles.
I dunno whats going on. If I increase the rpm to 1100-1200 the BLMS are steady as hell.
Its just on idle. Perhaps its "normal" with a all the SA corrections thats going on during idle?!

Cheers