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-   -   Running on 3cyl (https://www.miataturbo.net/megasquirt-18/running-3cyl-38495/)

naarleven 08-25-2009 05:43 PM

Running on 3cyl
 
1 Attachment(s)
So my car when started cold (even though its <90f out) now decides it wants to run really rough (what I'm guessing is 3cyl - sounds like subby, lotsa shaking, vacuum bouncing around). Once the car gets warmed up it runs fine. What in my tuning could be causing this?

msq attached and I'm going to attempt to datalog it in a few.

p51hellfire 08-25-2009 09:43 PM

hrmm I've had this on occasion I'd like to know as well, only on cold mornings then it won't for the rest of the day untill the next morning sometimes lol. I don't think it's tunning though IMO it's a bad ring..... IDK.....

naarleven 08-25-2009 10:03 PM

I mean I have 10k on this engine (rebuild) so I'd be mildly (understatement) pissed.

y8s 08-25-2009 10:57 PM

check plugs, swap wires?

naarleven 08-25-2009 11:07 PM


Originally Posted by y8s (Post 446622)
check plugs, swap wires?

I'm on that tomorrow. I am just trying to think why it works fine once I start driving. Wondering if it has anything to do with my cold start settings.

My cranking pws are all fucked up I know.

p51hellfire 08-25-2009 11:12 PM

I'm running the base ms map settings (besides tune) from diy auto I wonder if I need to start tweaking shit..... but where to start....

y8s 08-26-2009 09:15 AM


Originally Posted by naarleven (Post 446623)
I'm on that tomorrow. I am just trying to think why it works fine once I start driving. Wondering if it has anything to do with my cold start settings.

My cranking pws are all fucked up I know.

read the nuts loosening thread to learn about metal's ability to change shape when hot. all you need is a marginal contact somewhere that doesn't make contact when it's cold and when it warms up, does.

On my civic, I had similar issues. would run rough when cold and warm up and run fine. it got worse and worse over time and I finally dug into it and found one of the plug wires had come un crimped at the spark plug connector end.

Braineack 08-26-2009 10:19 AM

lower the fixed map value in your ASE settings.

Hakan 08-26-2009 10:30 AM

I was just fiddling with the fixed MAP value today, trying to remedy my bad cold starts. What is the theory behind it? I read the manual but didnt feel enlightened. The car starts, stutters and after 5 secs either catches on and purrs, or dies. Second attempt is always buttersmooth.

Stay safe

H.

Braineack 08-26-2009 10:32 AM

basically the MS fuels based on the MAP value you give it.

so if you have 80kPa in there, it fuels off your 80kPa row in whatever column your engine speed is at. Then it slowly decays back to your actually MAP value. If you're too rich itll run shitty for a few second before it levels out.

Hakan 08-26-2009 12:01 PM

Thanks. Its a pity you only get about two chances a day tops, to tune cold start. IŽll change it around and see what happens.

H.

p51hellfire 08-26-2009 01:36 PM

i adjusted my ve and spark tables today and it idles amazing!!! we'll c in the morning.


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