Injector dead time?

[mx-sid]

Sup y'all,

I recently installed a megasquirt into my BP'd MX-3. PNP version 3.3~ I have been playing around, getting familiar with it and finally have a decent map, I think. My idle still sits low MOST ov the time and it constantly bounces around, by about 50 rpm. I'm not sure if that is good, normal or too much.


I also haven't found what I should have my Dead-Time set to. In TunerStudios it says it should be AROUND .9 but mine is set to 1.3. What should my dead time be, using bone stock injectors from a protégé lx? All help is appreciated.


As a side question. How far do most ov you have your spark advanced? I'm N/A right now. I think the start up tune had like 37 degrees in a lot ov the places. That seems really high to me. I knocked it down to about 30 for the max. Is that too low? I think I read that once I order my turbo kit, I will have to drop it to around 16~..? maybe less. guess it depends how much boost I'm throwing down... BTW they have 93 octane at the pumps here. THANKS!!

[farcryNZ]

Hey man. I can’t help you but I hope someone can!
I’m building a ms for my car at the moment so stuff found here on your thread may be of use to me,



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[FE3-323]

have you reached out to lex (stratified)???

[nickz]

you look to be running lean, you have wideband?

[mx-sid]

Yeah I have wideband. Sorry about the slow reply, went on vacation.

I didn't get mine through stratified, I went through DIYautotune. But, if Lex doesn't care, neither do I. Hahaha!

Anyways, some info about my set up.
My REQ FUEL is set to 12.2
I'm using SPEED DENSITY, and all my GENERAL SENSOR SETTINGS are 50 except my Lambda, which is 60.
my Barometric Correction is set to all 0's? is that right?
My injector dead time is set to 1.0. It started at 1.2 I moved it down. it helped. I'm thinking about trying for 0.9 maybe..?
Battery voltage correction is 0.200 and Different bank settings is OFF.
My IDLE ADVANCE settings are also turned off. I think I actually just noticed those...
My dizzy is set to 4G63
Trigger angle/offset AND cranking advance are both set to 10
My Closed Loop Gain is 350
I also kept my Accel Enrichment OFF Don't remember why. tried turning it on, didn't like it for whatever reason..?

When it first starts up, on hot days, it immediately dies. If I give it some throttle, it bogs down for a few seconds then stays running. I have to baby the throttle until it gets out ov warm up enrichment, then it runs great. Kinda feels like it's flooding. I auto tuned the warm up enrichment. It dropped the curve super low like a line, which helped, but only a little. If I turn the car off and on again a couple times, it does the same as starting on a hot day, but gets worse the more times I restart the engine. which makes me think it's just getting too much fuel.

Once warmed up, it runs great. However, sometimes, when I put in the clutch, the RPMs jump up from a nice happy 750ish to like 1100. But it doesn't do it every time. Maybe a loose ground in the engine bay? I have no idea, but it only does it when I push the clutch pedal.
Suggestions are always appreciated Thanks!!!

[FE3-323]

there should be a setting for miata CAS not 4g63. that seems off to me

[mx-sid]

I'm looking through the different dizzy options, there is an option for Miata 99-00, CAS 4/1, and Miata 36-2. I'm guessing that 99-00 is the years it relates to, which isn't me. Not sure about the CAS 4/1, But I'm pretty sure the Miata 36-2 is a missing tooth configuration. I don't think the BP runs with missing tooth. I was pretty sure the instructions that came with it said if I had distributor to use the 4G63 setting. So far I haven't really had any issues with my spark that I know about. If you are running with a different setting and having good results, is there a place I can look at your MSQ? I would also like to see other peoples set up's for ideas. Thanks!!

[FE3-323]

4/1 is what all of the non miata BP's have
theres been enough development it seems to differentiate between miata 99-00 and 4/1 which I find intriguing
most of the miatas AFAIK are 4/2 at least the ones with coilpacks & wasted spark

[mx-sid]

Oh really? That sounds interesting. I don't suppose you know what the difference between the 4/1 and the 4G63 is? I don't really Understand the differences between the different settings, probably just different frequencies/ohms? I don't have coil packs, just the factory ignition coil and distributor. Could that be the difference?


Also, does anybody know what the difference between "wasted spark" and the other setting are? I didn't understand those settings options at all! I just kept it on wasted spark and hoped for the best. Hahaha!

[FE3-323]

wasted spark really only runs if you have 2 TDC signals. unless its powerful enough to calculate it (i don't think all MS's are)
in terms of 4/1 vs 4g63 theres a vast difference in position of home signals. which can cause you all sorts of grief. let alone there are 2 pickup home signals on a 4g63 disc for running wasted spark.

hope that helps some

[mx-sid]

Makes me think I have it right then. I mean, aside from being a total noob to this, my install and start up went really smooth. The only issues I have had were, dropping my dead time to 0.9 made the neutral safety switch drop the RPMs, in gear. At dead time 1.0 it's reversed. RPMs go up, in gear. When the dead time was at 1.2 (that's where the software had it for start up) I didn't really notice the neutral safety switch having any effect on anything. I think the reason I started messing with dead time to begin with was because I hadn't figured out that idle duty is how to adjust the idle speed. But I haven't taken the time to really mess with it. Also, having the dead time at 0.9 made acceleration feel sluggish. I'm thinking about going up to 1.1 or even back to 1.2.

I honestly don't understand where the spark becomes wasted. Or what it effects as far as engine performance. That is what setting it started with and I just don't know what changing it will do, so I leave it alone.

I also have issue with After start when it's really hot out. But I think I can adjust the curve or # to fix that issue.

I also don't know what pick up home signals are. Guessing it's what tells the computer where the engines rotation is..? Using 4G63 the little car is pretty peppy. If the home signals were all wrong, it would run like crap, right? I'm going to be making some changes to my tune tonight or tomorrow. Suggestions are appreciated!