Specs: 1985 GMC S15 with a 3.4l from a 1993 Firebird. Has the GM 220 TBI with 7747 ecm.
I am currently running a modified ATKX bin. (it's an ansync bin)
Since it's been at least 6 months since I've done anything with this tuning, I've forgotten why I am using that bin.
About a month ago now, I had to replace a freeze plug in the driver's side of the block. That sucked. While the cooling system was empty, I also replaced the radiator with a factory original from a 1988 S10 that was super clean. I've noticed since then, it seems something is different. I'm thinking that the temp is either more stable, or flow is better.
It seems to idle smoothly after warm up, and I know there are cells in the VE and spark table that still need tweaking, but haven't had time for that.
While driving home this morning, I noticed something that I've not noticed before, which was during a constant speed with a slight coast, the INT seems to go wacko. It seems to have just started. I got thinking maybe the O2 sensor maybe getting lazy, but it's only a year old. Map readings look ok, unless I missed something.
Looking at the cross count, O2 seems ok, but I've not found what the lowest count is acceptable. I've read that the O2 sensor should cross the .45 volt mark once a second, or about that. Looking at the log attached, it doesn't, but shows the counts being on average of 80 and up with some dips in there.
Part of me thinks that it's the weather change that is affecting all this.
Part of me thinks I should go back to the 1228062 ECM/BIN combo and stick with tweaking a BIN for 60 degree engine.
I hate the idea of feeling like I am giving up, but I just can't seem to find the time truly needed to tune these 90 degree bins.
Any thoughts, criticism and/or ridicule is accepted.
NOTE: the attached bin is a $42
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