Now I think I have this one figured out... kinda sorta maybe.

So it's been colder in the morning the last few days, and starting the Miata took about 4 tries. When it finally cranked over, it sounded like it was idling on three cylinders (probably just because the idle was so low, around 5-600 RPM). Wideband shows off-the-charts lean, throttle input causes stall.

Giving it a couple minutes, the idle raises and settles into a mode I've dubbed "rev like a ricer at all of the traffic surrounding you" because the revs surge a full 1k RPM, from 1400 to 2400. This becomes progressively less intense and by the time I'm at work, the surge has been replaced with a persistent idle sag at throttle lift accompanied by a stall.

So I'm thinking I should richen up the warmup to take care of the first bit, but doesn't explain the surging.

What confuses me even more is that in the afternoon, the car starts on the first crank, idles normally, doesn't die at stop signs, etc. All it does in the afternoon is buck back-and-forth like a rodeo bull at certain low RPMs while cruising, which it also does in the morning.

 

its all ASE and warmup wizard.

starting is due to poorly tuned cranking PWs.


log the event and analyze it or post it here for us to do your dirty work

 

I would be happy to oblige, but can't figure out what's happening to my datalogs on this (borrowed, Vista-equipped) laptop I'm using. It's like they disappear! Any thoughts?

 

there will be a button on the file browser....says "compatibility files" click that, viola.

 

Couldn't find said button (maybe I'm blind), but I found my old-*** USB drive and logged to that driving to work just now. I'll upload when I get home!

 

things that save into program files actually save in a different folder.

 

http://www.fileshost.com/en/file/466...drive-xls.html



edit - I'll attach a .zip version tomorrow, if I can get winzip to cooperate. I keep trying to create a new zip file, but it wants me to select a zip file to zip.. or something. I suck at computers.

 

I think I got it, LMK if this doesn't work please!

 

 

ttt

Here are the maps associated with the datalog.

after start:


constants:


fuel:


spark:


idle:


idle continued:


acceleration:

 

No one?

It's ok though, seems I have a date with the dyno!

 

The dyno's not going to help you with drivability issues. Only some trial and error will get you 100%. I'd start by looking at your cranking pw's. Most of them are best guestimation on my part, and may not be properly calculated.

 

I found that running closed loop idle is a bad bad idea unless your idle mixture is sorted out first.

Also, the rodeo bull behavior you describe is on account of the bins from 26-35 kPA at your cruise RPM being too lean. If it goes below 16.5 -17 AFR it does that.

 

I think that came out wrong when I typed it, I know dyno won't help with driveablility, just excited to have a day in the books. What was it you said about my WB02 not being trustworthy, Ben? I remember you said it seemed fishy that the car liked to idle/cruise so lean, well I guess it decided it doesn't like to after all!

I have cranking just about sorted, I used the excel calculator from here to get in the ballpark and then leaned a little more from there, and so far so good. Now the only thing is the idle/cruise, which I'll go richen up.

 

Here's a log from the afternoon:

 

Yeah, I found it rather odd that the car was running so well so lean. But the other issue is that your WB doesn't read anything leaner 18:1 I think (the screen just makes dashes). Unlike my LC-1 which will pretty much read anything up to straight oxygen. And my car runs fine in cruise at 19:1, but bucks at anything leaner.

You really just need to dump in HR and drive around for a few days letting VE Analyzer do all the heavy lifting. I've had about a half dozen miata enthusiasts drive my car over the past few days, and they've all been blown away at how smoothly it does everything. All I did was set up a good target table and let the software do all the work. Car's never run better.

 

Once I got MLV working correctly I've never been happier with MS. It really is an amazing tool for people using Megasquirt. Sometimes it takes a little doing to make it work right but when its does its abilities are worth the registration fee.

 

O RLY?

I've seen a few peeps going to HR, but I'm afraid I don't grasp the benefits. What are the advantages over my, uhh, "low-res" code?

 

For all I know, MLV is working correctly for me, in that I make a datalog, and MLV makes a graph. I was also not aware of any associated fee???

 

Better gas mileage, leaner idle, leaner cruise(better mpg), smoother running overall.