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-   -   trouble starting up below 70* (https://www.miataturbo.net/megasquirt-18/trouble-starting-up-below-70%2A-90675/)

curly 02-04-2017 08:29 PM

Uh....It is actually. As far as I know. Cranking generally happens right at the 100kpa (atmo) range, and I'm pretty sure cranking is just an added percentage of the fuel table. Plus a lot of other math.

But I could be completely wrong.

babydriver 02-04-2017 08:41 PM

2 Attachment(s)
msq and log attached.. (although i havent read much about logs and i have no idea what to make of it)

also a video of startup. coolant was probably ~55* outside temp was low 40s.
https://youtu.be/myBoHXWDILs

I guess I did not know that the fuel table wasn't factored in during startup.. but it seems like when I changed the table it affected startup but maybe that was my imagination

thanks for your help dudes. I do appreciate it because I've read all I can stand to read on this and still can't figure it out. I will be glad to paypal $10 beer money to whoever makes it right.
while you're having a look at my msq.. my injector ccs are set at 240, but this page Fuel Injectors - Miata Turbo FAQ says 254 in the pic, then 265 in the text below.. that was set by rev so I didn't mess with it.. was he just being conservative? also.. is it 254 or 265?

babydriver 02-04-2017 08:42 PM


Originally Posted by curly (Post 1390708)
Uh....It is actually. As far as I know. Cranking generally happens right at the 100kpa (atmo) range, and I'm pretty sure cranking is just an added percentage of the fuel table. Plus a lot of other math.

But I could be completely wrong.

so i might not be crazy hah

southernmx5 02-04-2017 09:51 PM


Originally Posted by curly (Post 1390708)
Uh....It is actually. As far as I know. Cranking generally happens right at the 100kpa (atmo) range, and I'm pretty sure cranking is just an added percentage of the fuel table. Plus a lot of other math.

But I could be completely wrong.

Cranking pulsewidths are based on a percentage of the reqfuel value only for both ms2 and ms3. The fuel table values are not used at all during cranking.

DNMakinson 02-04-2017 10:10 PM


Originally Posted by southernmx5 (Post 1390719)
Cranking pulsewidths are based on a percentage of the reqfuel value only for both ms2 and ms3. The fuel table values are not used at all during cranking.

Correct. However, as soon as start RPM is reached (commonly set as 300RPM) then the VE and Spark tables come into play.

southernmx5 02-04-2017 10:54 PM


Originally Posted by DNMakinson (Post 1390722)
Correct. However, as soon as start RPM is reached (commonly set as 300RPM) then the VE and Spark tables come into play.

Yes, which in this case is 350 rpm. OP misunderstood how to tune cranking conditions based on the previous post.


Originally Posted by babydriver (Post 1390525)
so my WUE, ASE, and cranking pw are now a lot lower/normal. The weird thing is nothing I do makes it better/worse. It always just starts like crap (cranks for like 3-5 seconds, small sputter, then catch) and runs fine once it catches. There must be some setting I'm overlooking. What part of my fuel table exactly affects startup? I'd guess the "below 500" column.. but does it factor in my idle rpm somehow?
.


southernmx5 02-05-2017 09:45 AM

The log posted appears to be a composite log of the trigger input. Please post a normal datalog of a cold startup attempt.

babydriver 02-06-2017 06:25 PM

dammit im having a hell of a time getting a log.. when i took an engine log during startup and tried to view it it says "no time column available".. i'm not trying to get pissed but my schedule doesn't let me spend much time messing with my car and i've spent all my patience trying to figure out how to fix my startup myself..

so tomorrow i'll try to figure out what i'm doing wrong with logging. in the meantime can anyone tell anything im overlooking from my msq (& video)? by this point i've tried everything from way too little fuel to way too much fuel and everything in between and the tune i posted is the best i can come up with.. it's driving me pretty crazy.


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