Sudden rough running [resolved] - Page 4 - Miata Turbo Forum - Boost cars, acquire cats.

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Old 04-27-2009, 10:52 AM   #61
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I have logs. Where do you want me to send them?
It happened again this morning but the log stopped short for some reason so I did not capture it. I have other logs though.

This morning's problem:
1. Drove with no problems about 15-20 miles at cruise, varying between 55-65 mph. Coolant temps at or below 200F.
2. Pulled into a drive-through. Car was idling high, like 1700 rpm. Never seen it idle this high before. Still running OK.
3. Car started warming up in drive-through.
4. Pulled back out into stop-and-go traffic. Coolant temp gets to the evil 205-210 temp range, and it starts running rough. Same symptoms, popping out of the exhaust, barely running, but this time AFRs were not lean.
5. I tried turning off the ignition and restarting twice, did not help.
6. I kept the car alive, barely limping along, getting "WTF" looks from other cars. Got back out onto the highway, limping along behind a slow gravel truck, until the coolant temp dropped below 200F. Then the problem cleared up and the car ran great again.

This is really getting to be a problem. I am probably going to have to park the car until I figure out what the deal is.
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Old 04-27-2009, 11:06 AM   #62
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Quote:
Originally Posted by ZX-Tex View Post
1. Drove with no problems about 15-20 miles at cruise, varying between 55-65 mph. Coolant temps at or below 200F.
2. Pulled into a drive-through. Car was idling high, like 1700 rpm. Never seen it idle this high before. Still running OK.
3. Car started warming up in drive-through.
4. Pulled back out into stop-and-go traffic. Coolant temp gets to the evil 205-210 temp range, and it starts running rough. Same symptoms, popping out of the exhaust, barely running, but this time AFRs were not lean.
5. I tried turning off the ignition and restarting twice, did not help.
6. I kept the car alive, barely limping along, getting "WTF" looks from other cars. Got back out onto the highway, limping along behind a slow gravel truck, until the coolant temp dropped below 200F. Then the problem cleared up and the car ran great again.
I could have written this, except for the part about it clearing up after it cools down to under 200. Once mine goes bad, it stays bad until it cools off from being parked.

Played hell keeping it running at the autocross yesterday in grid. If I carefully feather it down to idle speed it will sometimes catch and start idling. If I just go to clutch in coming up to a stop it will die.
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Old 04-27-2009, 11:16 AM   #63
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I think I may try reverting back to firmware N instead of O. What the hell, I am willing to try just about anything at this point. According to this post at Adaptronic, one can still run firmware N with the latest version of WARI
WARI update
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Old 04-27-2009, 11:43 AM   #64
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I was just wondering how much of this is tied to our bigger injectors. I'm on 600's, you are on 550's. I didn't have this problem until I went up from stock injectors. (I'm not going to reinstall the stock ones to test this theory, though.)
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Old 04-27-2009, 11:50 AM   #65
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That is an interesting idea. I do not blame you for not wanting to reinstall the stock injectors just to test the theory. Though I said I would try anything, I am not interested in doing that.

What is your injector current set at? IIRC mine is at 0.9A. Peak-and-hold or whatever that is called is checked (enabled).
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Old 04-27-2009, 12:11 PM   #66
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have you guys been through your coolant and air temp based spark trims at all?
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Old 04-27-2009, 12:12 PM   #67
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Quote:
Originally Posted by ZX-Tex View Post
What is your injector current set at? IIRC mine is at 0.9A. Peak-and-hold or whatever that is called is checked (enabled).

Set at Full Sequential 1-2-3-4
0.9A and peak-hold is checked.

Same settings were used when I had my stock injectors, FWIW.

I've never modified any of these settings.
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Old 04-27-2009, 12:20 PM   #68
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Quote:
Originally Posted by y8s View Post
have you guys been through your coolant and air temp based spark trims at all?
+1 on Matt's comment. It all seems related to spark and coolant temps more than fuel.
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Old 04-27-2009, 12:24 PM   #69
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have you guys been through your coolant and air temp based spark trims at all?
No, because I wouldn't have a clue what I would be doing or whether to raise or lower.

I just looked-wouldn't those corrections only work in closed loop?
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Old 04-27-2009, 01:29 PM   #70
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I dont think the air and coolant temp spark trims are closed-loop dependent. the ECU doesn't need to know your AFR or advance to add an arbitrary amount of either.

for now, just make sure they're close to flat lines at zero. (corrections tab, bottom middle in the ignition section "coolant trim" and "air temp trim"). edit: or copy mine

Also while you're both in there, check out the coolant temp and air tem fuel trims just above that. "coolant enrichment" and "air temp correction".

Here's more or less what I pulled from the hydra and my experience:

Air Temp Fuel Trim:


Coolant temp fuel trim (30 and 80kpa same for now):


Air temp spark trim:


Coolant temp spark trim:
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Old 04-27-2009, 02:39 PM   #71
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Matt:

That's good info. Mine are all zero'ed now.

As an update, at lunch today, while fully hot, I was having a bitch of a time keepign it from dieing. I couldn't even start it without catching it and keeping it going.

On the way back to the plant going down the highway I came to a stoplight. Let off and it wasn't slowing down. Kicked in the clutch and it was holding a 3,000 rpm idle. After two seconds it kicked down. That has never happened to me before, but I think it has to ZX-Tex. Funny thing was, after it kicked down it idled great the next three stops with no idle droop which also never happens. Just fell to 1100, held a second and dropped to 1000.
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Old 04-27-2009, 03:29 PM   #72
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I applied the settings above but did not see any changes that would explain this since all of the corrections were already pretty low or zero at the temps we are talking about. Plus it comes on so suddenly (2-3 seconds from fine to really bad) and severely that if it were a correction map setting issue it would have to have a really sharp rise in correction value right at the coolant and/or AIT where the rough running point happens.

Two things I did change drastically were the 'cranking fuel' and 'coolant enrichment high map' settings. Since they appear to be straight dwell settings, I reduced them all by about half since presumably they are set up for stock injectors, not 550cc injectors. I thought the car may have been too rich at startup so that should help.

I'll try the resulting new map on the way home. But it is raining hard here now and probably will be raining for awhile so the car will probably run cooler as a result. Thus I may not be able to duplicate the problem.
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Old 04-27-2009, 03:42 PM   #73
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It's raining and 45 degrees here. I can assure you that it will still be warm enough to happen. It did for me.

I did cut cranking fuel to compensate for larger injectors. I messed with coolant enrichment a bit but not too much. Ended putting it back to where I started so I didn't hose something up that I shouldn't have been messing with. I was doing it while I was out logging and it did make immediate noticeable changes if I changed the cells the covered the current (100*) temps.
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Old 04-27-2009, 04:03 PM   #74
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Quote:
Originally Posted by y8s View Post
I dont think the air and coolant temp spark trims are closed-loop dependent. the ECU doesn't need to know your AFR or advance to add an arbitrary amount of either.

for now, just make sure they're close to flat lines at zero. (corrections tab, bottom middle in the ignition section "coolant trim" and "air temp trim"). edit: or copy mine

Also while you're both in there, check out the coolant temp and air tem fuel trims just above that. "coolant enrichment" and "air temp correction".

Here's more or less what I pulled from the hydra and my experience:
The air temp fuel trim I did for them. The trim they have just based off of an empirical formulation of density at varying temperatures. Their zero temp is different from yours though so it looks a bit different. I will load the rest of your trims into the standard map pack though. That may help out cold driving a great deal.

Rob has the maps and logs, but he hasn't got back with me yet.
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Old 04-27-2009, 05:03 PM   #75
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you know, the more I think about this, the more I think it's an electrical load issue.

part of my issue with the hydra was that the way it was hooked up didn't take extra loads into account (other than primitive a/c idle up). when a fan came on, the idle would go to ****. god forbid I try to drive on a hot night when it was raining! (wipers, headlights, defroster, a/c) My idle would be all over the place.
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Old 04-27-2009, 05:14 PM   #76
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Originally Posted by y8s View Post
you know, the more I think about this, the more I think it's an electrical load issue.

part of my issue with the hydra was that the way it was hooked up didn't take extra loads into account (other than primitive a/c idle up). when a fan came on, the idle would go to ****. god forbid I try to drive on a hot night when it was raining! (wipers, headlights, defroster, a/c) My idle would be all over the place.
I did play with the electrical load "extra effort" but I forget if it affected it at all. Most times, I move everything back to "where it was before" before saving the map if I'm not sure.

My issue is with everything electrical off, except the fan. I may try moving the "fan on" to some value above 105*C instead of 93C for a test period to see if that rectifies my problem. That said, I'm over 100* within a mile of my house and the first stop or two after that it can be fine. It's almost that it has to heat soak to make the problem crop up.

I think that it is somewhat related to fuel as it is richer when cooler with the current coolant enrichment map, but when I increased the enrichment at 100* to the 70 or 80* levels (when there is no problem) it didn't help.

Regarding my earlier reference to heat soak, other items that may be an issue spark related are plug wires and coils. It could explain why, while the motor is up to temp the coil and wires could still be cooler and only after they have a chance to heak soak the problem comes up? I don't know, just throwing out ideas.

That said, wouldn't the problem show itself at upper RPM's as well? Or could bad plug wires run OK at higher RPM and suck at idle? Most references I see are 5K and above falling on their face.
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Old 04-27-2009, 05:18 PM   #77
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Y8S, it could be. Some of the time when it happens I have a lot going on. Fans on, A/C running, inverter powering the laptop (cigarette lighter), stereo on...

However though, I can jump in the car with the engine cool, have all of these things running, and still not have an issue. It has to run for awhile before there is a problem.

I did notice in the latest log where I captured the rough running problem (it was an idle condition) that the voltage logged by the ECU dropped a lot. I do not know though if the low voltage is a symptom (from very low RPM during rough idle) or the cause (something causes a voltage drop and the problem begins). Based on the timing of the log it looks like the rough running started before the voltage drop so I suspect it is a symptom. This last time, the a/c was not on, and I was not running the inverter. The radiator fans were on though.
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Old 04-27-2009, 05:24 PM   #78
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try DROPPING the fan switch-on temp to 70 and see if it runs shitty all the time.

remember, when the voltage is low you may have issues generating a hot enough spark. either of you running COPs or a capacitor on the ignition?
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Old 04-27-2009, 05:28 PM   #79
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I did notice in the latest log where I captured the rough running problem (it was an idle condition) that the voltage logged by the ECU dropped a lot.

Interesting. Now that I have been using MegaLogViewer I only turn on values that I'm looking for so I would have missed that completely. I'll check my latest log tonight. I know exactly where mine started to go bad on me.

There is specifically a low battery "extra effort" cell that likely is set to 0 in WARI. Mine is. Wonder if that might help?
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Old 04-27-2009, 05:59 PM   #80
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Quote:
Originally Posted by y8s View Post
try DROPPING the fan switch-on temp to 70 and see if it runs shitty all the time.

remember, when the voltage is low you may have issues generating a hot enough spark. either of you running COPs or a capacitor on the ignition?
The other day I tried lowering the fan temps to where they were both on all the time and it made no difference.

I am running Toyota COPs, dwell set at 2.5 ms. I think Stein is running factory coil packs.
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