Short version, per the headline: what numbers should I use for cranking dwell and running dwell on my MSM (parallel MS, stock coils)...?
Long version: my settings were 3.5 and 2.5 since the beginning of recorded history (last summer when I first 'squirted). Also I've had misfire problems at idle for almost as long. From last summer until now, I've tried myriad things to address the misfires .... new plugs, new wires, new coils, DIY spark mod (which worked for a short time and then stopped working), several fuel injectors, a whole new injector harness (which it turned out was needed anyhow) .... plus a bunch of headaches, a bunch more money, and massive bunches of my time and Paul's.
As a last resort I decided recently to attempt COPS. The concept of "dwell" came up during this process thanks to y8s, Jason, and Sam. I have to admit that until today I had NO CLUE what dwell is all about. Sam explained it to me in an IM tonight. Then he said my settings were too low, so we both checked with AbeFM who also had an NB. He suggested that I use 5.0 and 4.0.
So with very little charge left on my laptop battery, I rushed outside and uploaded the changes in a new msq (didn't have enough juice to do any datalogging)....
Initial impression: car started MUCH stronger .... it no longer lingered on lean AFR for a few seconds as it's been doing the past few months, but instead jumped right to properly rich settings .... good stuff.
Then I warmed up the car and went for a short highway drive, maybe 15 minutes at 70mph .... exited, stopped for a red light .... no misfires!!!!!!!
One negative thing: this change somehow mangled the idle itself. Before, despite the misfires, idles was stable around 850. Now it's not misfiring but the idle kept jumping up and down between nearly stalling (600) and way too high (1300) ... what's going on here???? (Normally that only happens for a short time after I turn the car off and start it again soon after, because of IAT heatsoaking, but that wasn't the case tonight.)
I repeated this test a couple of times. Highway driving, exited, no more misfires but retarded idle. LOL so I traded one problem for a new problem.
Meanwhile, I also cleared the misfire CEL before I left my driveway, and it stayed off the whole time tonight. So that's a good indication.
If I can fix the idle, then I might sell the COPS that I just bought .....
PS - I read the thread at http://www.miataturbo.net/forum/t11744/
and only partially understood.