Cold Start: Success! (also, I'm a dumbass)
 

Today at lunchtime (CLT = 70°) my engine fired up and roared to life on the first turn of the key!

The back-story:

Since installing the MS about three weeks ago, I've waged an unending jihad against this massive cold start problem. I'd engage the starter, after a few seconds it'd cough, catch, run very poorly for a moment, then stall. Sometimes I could keep it running on the second or third try by working the throttle, sometimes not. Generally, by the fifth or sixth attempt I could manage to get it running by pumping the throttle and then holding it at about 2,500 for a minute or so. The neighbors were not enjoying this serenade every morning (fortunately, no fighting was necessary. ;) )

Every morning I played with the cranking fuel, ASE, and warmup, throwing larger and larger numbers at them until I practically expected to see gasoline pouring out the tailpipe, but nothing. Always the same result: crankcrankcrankcrankcrank *sputter* ... *sputter* ...stall (repeat). I was really starting to worry that some night I'd kill the battery doing this.

It's been driving me absolutely nuts! I've been re-checking the hardware, using the 'scope to verify the injector timing relative to stock (it is slightly off, but not much), fiddling with values, cursing rather loudly, and just generally running around in all directions wondering where the hell I went wrong.

Last night, while on my second bottle of Deschutes Brewery's Black Butte Porter, I said "To Hell With It." I decided to try going back to 029v (from HR10d2) and generating a whole new MSQ from scratch. As I was about halfway through the process, I happened to notice a setup window that I'd overlooked previously. It's under Advanced -> Fuel Table Selection.

Holy freaking shit.

No wonder it felt like it was firing on 2 cylinders and that my changes to Cranking and Warmup were having no effect- it's because they weren't! With regard to the attached picture, the boxes highlighted in red default to OFF, and must be manually set to ON. Otherwise, you'll only be squirting two injectors during cranking, and all your precious warmup enrich values will be for naught.


http://img256.imageshack.us/img256/1...eltablexd2.gif


I can't believe I am such an utter, total, dumbass to have missed this. :vash:

LOL,
The reason for on/off on each channel likely has to do with rotaries :)

Glad to hear you figured it out. When there is a ^ i always make sure it's active. :)
You're boosting around town right? Or have you been babying it.

So that's the significance of ^, then? I don't recall seeing that in the manual. I also went back and re-read both the main megamanual and the MSExtra-specific manual, and I couldn't find a single reference to these settings in any of them...

cjernigan, I have been boosting, gently. I haven't yet installed EBC, and I've got my MBC bypassed, so I'm running on base can pressure- about 5 to 6 PSI. I haven't really romped on it much since the VE table still needs a good dyno session, but I have been boosting mildly. I'm really impressed by how totally seamless the transition into boost is with this setup relative to the EMU- no sudden jump in AFR, just a nice, smooth curve.

[quote=Joe Perez;213778]So that's the significance of ^, then? I don't recall seeing that in the manual. I also went back and re-read both the main megamanual and the MSExtra-specific manual, and I couldn't find a single reference to these settings in any of them...
quote]

If you look at the top of that window it shows ^ = MSnS default :noob:

D'oh!

Kinda seems like something that is called a default ought to actually be the default, wouldn't ya think? :nuts:

:werd:

Hey thanks for sharing your 'dumbass' moment. Considering the complexity of the task I would not feel too bad, though I am sure the frustration level was high, been there, done that. Who knows, someone else may have the same problem and find this post.

If it makes you feel better, I too had a recent attack of acute intercranial rectitis I will share. The other day when doing my brake job I forgot to torque the lug nuts on the rims. I only snugged them before lowering the car off of the jack. So the next day I am driving around, and I hear this clunking coming from the front of the car... Sure enough, loose lug nuts. To top it off I forgot to put the tire iron back in the car and had to borrow someone else's. :vash:

Granted, my problem was slightly more obvious than yours :) Really sucks those settings are not documented in the manual, nor the default settings.

There are a lot of settings that don't make sense by default. But, wow! You MS-I guys have some weird stuff to keep track of - and weird units, 1/Pw divide by 4 and stuff? Ick!

And to think I have a spare MS-II chip just wasting away in my drawer....


Ha! I did that exact thing, I pull over, pop my trunk, and Mike H. from the local Miata club pulls up to show me his new wheels, and unknowingly to lend me his wrench.


This brings in a nice side project I want to do, when I find someone who wants to do it for me. :-) I want to make a script for concatenating log files. MegaLogViewer has a nice autotune function (if you keep an eye on it), and I have log files at probably 6 different boost levels. I could do all my tuning in one go, averaged over a huge range of settings and with hours of log-time, but I want a way to string them together.

Any ideas? They are just .xls, and you have to do a small amount of tweaking (remove/renumber the manual mark/resets, and maybe the timestamps need a touch up. I should make another thread for this, see: https://www.miataturbo.net/forum/showthread.php?t=17033

And this evening (CLT=65°) it again started near perfectly on the first turn. :bigtu: I cannot begin to express how full of joy this makes me- not being able to start my car like a normal person for several weeks was really bumming me out.

You guys are scaring the hell out of me, 60-70 being a cold weather start:eek5:

I'm hoping to install two different standalones this spring with temperature ranges from 30 to 100 degrees. By the time it is below 30, the car is in storage.

I sure have a lot of learning to accomplish in the next 9 months.

60° is damn cold, my friend! I've had the heater on in the Miata (top still down, of course.)

In all seriousness- the problem I was having wouldn't have been much different if it was 20° or 80°. Half my injectors weren't squirting at all during cranking, and I had zero warmup enrichment thereafter.

Another frigid 60° morning (and with water mysteriously falling out of the sky, no less) and another perfect, first-turn cold start.

I know this thread has reached a new level of retardation, but I just can't adequately describe how deliriously giddy it makes me to be able to start my car!
:yippee:

I started a thread on this issue over at msextra.com, we'll see if anything helpful comes of it.

Low 20s here this morning, 60 degrees doesn't even hit our cold start tables:)

Congrats Joe. It's always a good feeling when it starts.

It is about 20-30 in KY now and I bet mine will start :p

Ah, "Lean-Start", imagine the improvements in mileage you're giving up.

One thing I HAVE noticed, they really aren't very interested in changing the code 'just cause it's a good idea'. Things like "Well, the widebands read wrong" is met with a 15 step work around that isn't documented anywhere, if you get any answer at all.

And why the MS-II *can* log data at 100 hz, but when I ask to be able to do it longer than 1 second, they just say no. And, when I suggest that maybe it's too much data, and I could log fewer things at a higher, useful rate, I get silence.

So, something like your car not starting would get ignored by the MS-IIxb guys.

Speaking of which, when does it start now? Mine takes at least 3 full revolutions, 2-3 to notice the motor is running, and then it starts almost right away. Yes, there's an easy fix, and no, they don't want to do it.

I haven't logged it on the scope, but it feels like it takes maybe one to one and a half complete revolutions before it fires. Basically, it feels almost exactly like stock. The only difference is that after it catches it immediately shoots to about 1,500, then wants to idle at about 500 RPM for a second, and then it settles.

I have been playing with the cranking (dc) value under IAC, I originally had 27 (the DIY default) and I increased it to 60 a little while back (which made the engine shoot straight to 3,000 the first time it started properly) and at the moment I'm dialed back to 40. 27 seems too low for my engine, I'm thinking maybe 35 or so will be the sweet spot. I've also got it trying to seek idle 0.5 seconds after start, which might be a tad too soon, but definitely feels better than when it was at the DIY value of 25.5 seconds.

Joe thank you! I've been having nearly identical startup issues and I'm in
80* weather, lol!!

Not sure if this is it, but def a good place to start!

Mine will start on the 1st try AFTER its been running for a while. But I guess its technically not a cold start then...I haven't even started working on that bc of other things I'm troubleshooting...

But thanks again!!!

I actually got my best info from watching it on the jimstim. Also, when I see the logs, I can see the manifold pressure fluctuate for a while. Then I see the timing signal have huge errors for a while. Then the fuel comes on and the timing and it starts probably the first time it fires.

And this evening we had a genuine, bona-fide cold one. CLT = 45°, and yet the beautiful MS-I fired perfectly on the first turn and settled immediately into a nice idle. IAC Cranking (dc) = 35 is definitely the sweet spot.

Ok, that's it. I promise I'll stop posting a message every single time I start my car from here on.

BTW, Abe- time to update that sig. Link Piggy w/ 300cc? O2 eliminator? Me thinks not. :D