[jeebus]

Originally Posted by jamesm

if your iam is 0.2 then you're damn near in limp mode. that's bad. log every knock param you can and see what is going on. it's very likely that you're running more than 3 degrees advance in the 0.5-0.9 load range, thus enabling coarse correction in this range where just about every 86 i've ever seen knocks like hell, and causing the iam to drop precipitously.

moral of the story: if you iam is ever 0.2, that's a #1 priority, figure it out now kinda problem. it may be that it's pulling 5 degrees under full load (bad) or as simple as tip in, low load knock messing up your day (not so bad), but in either case you want to know and want it fixed.

you iam should be 1. all the time. if not something is wrong. it can be argued that our car drop iam stock, so it must be ok. but it's not, the stock tune just has knock issues. the point of tuning is to make it better than stock .

fwiw i'm still not able to get rid of all the knock (i get -1 and -2fbkc occassionally down there), so i just disable coarse correction in those areas. bad idea? maybe, but i've seen no ill effects thus far. it still knocks less than a stock 86 lol.

It seemed to be all transient stuff causing it. However a fresh tank of gas seems to have corrected the issue. Must have been some bad 91.