take a look at my log
 

look where duty cycle drops to 0.0 while at about 14.6psi at about 353.627seconds and turns back on at 353.771s, i'm not really sure what's going on here, can this be a misfire? i had gotten gas and the problem seemed to go away but now i'm looking back at my log and it looks like my injectors just turn off

Detonation maybe definetly not lean if you look the AFR gets richer there. If th egas helped the problem then it was probably a octane issue.

i have an LM-1 wideband handheld, in boost it never goes leaner than 12:1, i even added +5 to fuel in all the boosted rows and it runs in the 10:1-11:1. I've also watched my opg for any funny jumping or anything it's dead steady, i also don't hear any pining or knocking, only a popping noise from the exhaust. I've also tried backing out some timing and that didn't help either. but then i got gas at my usual mobil location after running some sunoco i got 2 weeks ago when out. It didn't do it after i got gas but i'll try it again as might have been just a coincidence since it doesn't do it every time.

I'm thinking overboost shut down.

i thought the same thing, my overboost is set to 205kpa, in that log i'm only hitting 201kpa. Unless it's happening too fast and it's not picking it up?

increase it a few more kpa because it sounds like overboost protection to me as well. maybe turn it up to 208-210 and see what happens.

i'll try it, i really hope i don't blow this thing up

ok i upped the overboost protection to 210kpa, doesn't make a difference. It's pretty much random and only when boost like over 12psi. doesn't always do it, sometimes will do it 3 times in separate spots in a pull. I have a feeling it's just a weak ignition system but why would my log show duty cycle going to 0.0? does that make sense if it's not sparking that it would do that?

After the thread from Magna about his nuts here:
https://www.miataturbo.net/insert-bs-here-4/pics-my-nuts-look-your-own-risk-like-anyone-would-ever-steal-these-wheels-5756/

I was kinda scared to look in here. :inout:

haha lol

I just got back in town at 5:42am this morning... long story but ended up getting shuffled around on flights and on the red-eye back to ATL with the fam... Hopefully you got a chance to send this off to our support desk last week as I'm sure Matt/Justin could clear it up pretty quickly. Looking at this logfile it really looks like overboost protection fuel cut to me. The CPU samples and responds to some of these parameters faster than the log rate so it's common for things like overboost protection to kick in when the logs still show you being a few kpa shy of the limit you've set.

Without seeing logs of the symptom occurring after you increased the overboost limit it's hard to see if it's the same thing occurring or something else. If you can send us a log, along with the current .msq file that the log was made with, we can help you get right to the bottom of it.

ok i upped the overboost protection to 230kpa. I couldn't get it to skip on me. It doesn't really make any sense to me, i logged the run i did and only hit 199kpa, when i had overboost set to 210kpa it was doing it, i just can't imagine the datalogging could be that slow, and if you look at the log i can't imagine boost would jump like that when i'm having trouble holding boost to redline as it is. i don't know i'll gradually bring down the overboost protection and see what happens.

yeah, there ya go.

We noticed on Ben's car (atl93) that if we set his overboost 20kpa higher than his target, it ran smoother than when it was 5-10 kpa over his target. This difference was noticable. There must be small 'spikes' that the ecu fuels off of, that are too quick to capture in datalogging.

oh well, what good is the datalog then? if it doesn't come back then i guess that's what it is.
maybe noise i the map sensor?

Do you have a inline filter in your vac line? Mine helped smooth out my map signal a bit. I used a motorcycle fuel filter just because I couldn't find the one at the local parts store.

hmm never heard of doing that, no i have no filter. I ran a vacuum line directly to the mspnp unit as per instructions

You can supposedly get one at advanced or autozone in the vacuum fitting settings that fits better than a bike filter.

I'd have to run it past the developers, but it's very possible that there is a predictive sort of behavior going on here, so that it sees the current boost increase trend is about to send you over your configured limit and stops it before it can, if that's the case and it let you hit the limit and then did something about it then it's very likely you'd go a bit over it before it 'caught' it.

Just a thought, I'm not sure if that's what's happening but I can certainly understand why it would make sense. In my experience setting the limit to about 10kpa or so over what I'm seeing in my logs is usually adequate. But then if there are times that you hit higher boost than others, due to different conditions, you risk hitting the boost cut again. It's not really there so you can say 'I want to run 200kpa, so I'll set this to 201kpa', it's a safeguard to shut things down if they're abnormally out of hand from where they should be.

i didn't think it was that smart, if so that's pretty neat. though i'd imagine people with faster spooling setups would have much more issues.

Jerry
So you are saying if his target max boost was say 240 kpa, on his 2.5bar sensor he would encounter problems at 220-230 kpa occasionally as well. An you would recomend the mapdaddy to remedy the situation then? This is good to know.