I've seen that, too, but this isn't a column, it's a row five or six cells wide and two deep where it sounds like the recirc valve is partially working, when I'm trying to hold a constant cruise speed. I hear a chuff, chuff, chuff, sound till I change rpms.

Sooooooooooooooooooooooo, since I'm still fighting with the idle settings, should I go ahead and upgrade to 1.5.0? I don't use EBC, but the rest of the changes seem interesting.

Thanks,

I upgraded to 1.5.0. Easy when you're not replacing four year old firmware. Lesson learned.

Gents,

Things are coming together, but I'm still a noob.

My research tells me the Priming Pulse and Cranking Pulse numbers are huge compared to other tunes.

Attached is yesterday's tune with 1.5.0 Firmware. Could someone please take a look and set me straight.

BTW, some things are turned off right now that will be turned on soon, and I know my WUE is way off.

Thanks,

What the heck does this mean?
 

Gents,

She's running great, but I'm still tackling idle issues. I noticed that since I turned EGO correction on I had wildly swinging AFR readings on the dashboard, and some flashing lights on the MTX-L, so I decided to turn EGO off. It got exponentially worse. I hit the spacebar when I made the changes back and forth. Attached are the current tune and a log idling in the driveway.

The car honestly runs fine, but I would have sworn the needle on the AFR gauge on the TS dashboard was actually spinning through 360 degrees. If the Bosch 4.2 O2 sensor is bad, that means they last about a year when going through tuning pains.

Any help would be greatly appreciated.

This is a guess: overly rich misfire. Is the engine idling rough during the episodes? EGO shows that you are 5% rich in the idle cells being used, and your target is already richer than stoichiometric.

Unrelated: fix the typo on VE cell 19kPa and 700RPM.

She was running pretty smooth while I watched the needle going crazy on the TS dashboard. I'll work on tweaking the idle cells. Still trying to make all the VE, WUE, ASE, PID stuff gel.

I have another issue. When I come to a stop after driving for a while, the idle is up around 1100-1200, then settles back down to 950 after a second or two. Seems to happen regardless of the coolant temp. I know I'm not through tuning PID, but was wondering what would be causing that.

Thanks much,

Oh, and thanks for pointing out the typo.

That's how it is supposed to work. Be happy.

EDIT: have you read ANY of the MS manuals?

Downloaded to my company computer even. I've been through it, but the manual lacks the Miata context provided here.

Thanks,

Strange High AFR Behavior
 

Gents,

I've been concentrating on getting the idle stuff right, so there's been a lot of time in the driveway. I've made lots of changes and tried lots of things. Regardless of the tune specifics (to the best of my observations anyway), after she gets fully warmed up I've had more than a few occasions when the idle AFRs moved rather quickly into the mid to high 16s. I thought it was just from sitting there in the driveway and getting heat soaked. Today, however, driving home from work it was beautiful, about 68 degrees. No speeds over 40 mph, but no stops for lights or traffic. No way heat soaking could be an issue. When I pulled into the driveway and stopped, the AFRs idling moved into the high 16s. Although I think the O2 sensor is fried, she sounded labored, not quite right, so I think the O2 sensor readings were correct at the time.

Something is happening, and I'm not smart enough to figure it out. I logged a short file in the driveway. I have two other logs from today, if they will help. The tune is essentially unchanged from the one in Post #85.

Any help would be greatly appreciated.

EDIT: She sat for over an hour with the hood up. Started and idled normally.

I'm too busy to look at your logs or tune, but have you tired simplifying your idle? Start by saving your tune, and saving it again as something stupid like "idle experiments". If your timing is swinging around at idle, make sure idle advance is off, then select the entire* timing table and set it to something simple, like 14*. Then make sure idle VE is off, fan is off, etc. Look at your idle valve, round up to the nearest whole percentage, open up the idle valve test window, and set it to that number. Then select the entire fuel table and set it to roughly what you're currently idling at. You should be able to adjust this single fuel table VE number to a setting that keeps AFRs and RPMs very steady. If you're not able to, something is mechanically wrong. If you are, then you know you're actual tune has issues with idle advance, idle ve, CL idle, etc. Start adding these features in one by one until you continue you have a smooth idle, especially after small throttle blips and such.

*Obviously you don't need to select the ENTIRE 16x16 fuel table, but you catch my drift.

Good Call, Curly. Back to the basics.

Gents,

I swapped in a new O2 sensor. That seems to have fixed the crazy swinging AFRs.

Question. If the Closed Loop Idle Initial Values table had excessively large numbers in it, would that result in high AFRs, supposing that the idle valve is open too far for the Idle Target Curve rpm?

Thanks,

No

Overrun Fuel Cut
 

Gents,

Here is the overrun fuel cut pulldown from my current tune. I enabled it and the car had a tendency to want to completely pull fuel in slow moving traffic. It seems intuitive I should reduce the TPS Lower Than% number, but is anything else awry?

Thanks,

Lowest RPM To Re-Engage (set for 1550) must be a smaller value than RPM Greater Than (set for 1500). I have mine set at 1800 and 2000 respectfully to give some buffer above when dashpot for idle PID.

Also, MAP lower than should be just below where you idle, so that you engage only in true over-run.

Gents,

I thought I had it conquered. I'm at VIR now and am having sync issues. Attached are my tune, and a log and composite log I got on track. Can the loss of sync cause any damage?

Any help would be greatly appreciated. I think I'm going to take her home.

Thanks,

Gents,

My rev limiter does not appear to be working.

Any ideas?

Thanks,

Gents,

I had a pretty good day at VIR yesterday, including two fantastic, error-free sessions. I beat my best time by 1.24 seconds. Twice. She did a 2:18.750 with the new tune. Then, she sh!t the bed again. I left the track early. She was purring like a kitten on the way home, so much so I was regretting leaving. There's nothing worse than intermittent electrical gremlins.

I was on a back road and pulled out to pass. The rpms weren't very high, maybe 4000 to start the pass. During the acceleration, I got a sync error. I set up a couple more logs. The small one is a short log with another sync error during another pass. The other includes a pull from a stop light that I'm sure goes higher in rpms, but there were no errors. I'm thinking I have either a computer hardware issue now, or I have a wiring issue.

As always, any help would be greatly appreciated.