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Old 01-19-2010, 11:02 PM   #1
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Default Emissions help/story

So today with a car that's finally running well, I took off after work for DEQ (department of environmental quality) to try and pass their test and then get my car's registration renewed, which expired 7/09.

I hoping for one of two outcomes:
1. Fail, get gas, go home.
2. Pass, celebrate, get gas, go home.

That didn't happen. I waited in the parking lot next to let the car warm up, as it's setup with a "racer" reroute. At 180* I drive up and get tested. They do an idle test and a 2500rpm test. I passed the HC portion, but failed with 1.2804 CO at idle, and 1.046 CO at 2500rpm. I was watching the whole time, and the temp stayed between 185-190, with the AFR's staying in the mid to upper 13's, and an idle of 800. The throttle seemed to be sticking a bit so I had my foot pressing up a bit from under the pedal to keep it at 800. My results were so close to passing that the lady said 10-15min more warm up and I'd probably pass.

After circling the block a couple times I park to let it warm up a bit more. At this point things start going wrong. I drive up for testing at 195*, but the temp is still climbing and with the fan on it seemed to finally settle at 220*. It was also idling at 1200rpm with an AFR in the mid to low 12's. I flipped the highbeams and blower on, using this electrical load to get it down to 1000 or so. With the higher rpm and lower AFR's, I bombed the test at 4.9109 idle CO and 2.06 2500rpm CO. End of emissions story.

Rest of crappy afternoon story: So as I'm staring at the guy's computer (after he said I didn't have a cat, cause he couldn't see it with his crappy mirror) and all the numbers on the screen start jumping around. A split second later I realized the car was starting to die. I looked over in time to see it's last sputters and an AFR of ---, full lean. Trying to start it resulted in a worthless sputter. If I floored it it'd go up to 2000-3000rpm, but wouldn't keep going. Limped it out of the garage with one of those flares of revs, rolled it down and out of their driveway, and parked it on the street. Poked around the engine bay, took the fuel pump cover off (no carpet FTW), but nothing seemed out of place. I finally concluded that I must be out of gas. It was sitting on E, but I could of sworn I had driven with it easily under that, oh well. Walked 3 blocks to the gas station, paid 10 EFFING DOLLARS for a 1 gallon gas can, $2.90 for a gallon of gas and walked back. Guess what? Nothing changed. I breathed deep, and flipped the MS off. I decided to reload my .msq, see if that changed anything. When I flipped the MS back on I realized the FP hadn't turned on. I reach under the dash and barely touch the vampire tap going to the green FP wire, and hear the familiar whine of my Walbro. What followed was a wet, one tire, burn out that lasted a block, and a drive home. End of my crappy afternoon story.

Questions:
What's the "best" AFR to tune for with emissions tests?
Leaner the better?
With the jump from 180* during the first test and 210*ish on the second test, does a 400rpm jump in idle and a 1.2ish point loss in AFR sound about right?
I also upped the running dwells on my COPs to 5.5ms, hoping it'd be a strong spark and burn as much fuel as possible. Good/bad/pointless?
Any other settings to play with for emissions?

Thanks in advance, maybe we could compile the answers to the above questions into an MS emissions sticky? This is assuming you don't just post a bunch of "cool story bro!" pictures.

Last edited by curly; 01-19-2010 at 11:24 PM. Reason: wordyness
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Old 01-19-2010, 11:10 PM   #2
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Curly,
Your story... lost me. To try to answer the questions at the bottom, you want to emissions tune at 14.7 and then activate closed loop EGO with a 14.7 target. You typically will want to run less timing advance than you would on the street. This will make the exhaust hotter, which aids cat efficiency.

Sounds like you might have some other issues going on with your idle control.

If you're running Toyo cops, you need to keep dwell down to 3ms. 5.5ms will do nothing good for your spark, and will possibly damage your coils.
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Old 01-19-2010, 11:18 PM   #3
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Thanks Ben, sorry for the long winded story. All my friends are busy, and my usual ritual of punching something usually ends up in me replacing whatever I punched, so I needed somewhere to vent.

I need to play with the idle controls. I looked at them while waiting for the car to warm up, but got completely lost and left them alone. I believe they're the MSPNP's numbers. Any ideas for specific timing numbers? I figure I'll select a portion of the table that will easily incorporate any and all idle/2500rpm ranges, and set it to a set value.

I'll put my emission's map's dwell back to 3.5ms, apparently I've picked up a misconception about them somewhere along the way. And yes, they're Toyota COPs.
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Old 01-20-2010, 12:14 AM   #4
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Cool story bro. I LOLed at running out of gas. Come on, you gotta admit that **** is funny as long as it's happening to someone else.

I'd follow Ben's advice for fuel- 14.7 in whatever cells you get tested. As for timing, the MSPNP base map is "conservative" (i.e. not wildly advanced) but probably still advances a bit more than stock. IIRC Paul (username=Paul, doesn't post here as much as he used to) had a timing table for MS that is supposed to help pass emissions. But I really think it's your fueling that's the problem. It's going to be difficult to pass with AFR in the 13s, much less 12s. This graph shows that you want to target a fairly narrow window. Too rich and CO and HC shoot up, too lean and you'll fail for NOx.



Also, friends don't let friends use tap splices, because they are the motherfucking Debbil. My experience with them in my truck tells me they tend to fail. Not soon, because they are fine for a year or two, but much later when they are more of a PITA to diagnose because you forgot you used them in the first place and you have no idea why the hell your cigarette lighter socket only gets power intermittently. In a high vibration environment like an aggressively driven Miata I'd expect those tap splices will probably fail sooner rather than later. Use something more mechanically secure like crimped butt connectors, or better yet, solder that junk.
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Old 01-20-2010, 12:19 AM   #5
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I'll most likely solder it. Beyond the spade connector I have at the other end of the FP wire, that tap splice was the last bit of my "temporary" MS install. When I started it for the first time the AIT was sitting on the radiator, and I was holding that wire into the FP relay.

Thanks for all the help guys. I'll start tuning around 180* instead of 160* (where my thermostat opens) and aim for 14.7, as well as look for that emissions friendly timing map.
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Old 01-20-2010, 12:59 PM   #6
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The DIY msPNP base map for timing is pretty conservative and might be the ticket.

My car's a daily driver so plenty of warm up isn't an issue for me. Mid 14's, running right, warmed up, crossed fingers and you should be golden. You have stock injectors back in it currently? I passed fine with my 550's in. If you have a good tune on those 460's don't be afraid of keeping them in. Better than throwing a quicky tune together on the stockers just for DEQ.
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Old 01-22-2010, 06:08 PM   #7
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2 quick questions before I leave to get the car tested again.

1. I've got the idle at 14.7afr, but they also do a test at 2500rpm, do I want the same afr there as well?

2. whats the ideal timing I want it set to, 12* like stock? at least thats what I think I set my timing too. And again, do I want that same timing at 2500rpm?
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Old 01-22-2010, 06:17 PM   #8
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Yes on number 1, that's a steady state cruise test, your motor is fine running at stoich, and this will help emissions.

I'm unsure on timing...but 12* sounds decent. It should advance a few degrees for every 1K rpm.
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Old 01-22-2010, 06:18 PM   #9
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14.7 & Less advance than stock.
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Old 01-22-2010, 06:39 PM   #10
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Alright, I'll set for 10* at idle and 12* at 2500 rpm, wish me luck!
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Old 01-22-2010, 07:40 PM   #11
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Passed with ease, thanks for all the help boyos.
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Old 01-22-2010, 07:55 PM   #12
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Badass!

Congrats.
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Old 01-22-2010, 08:05 PM   #13
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Old 01-22-2010, 08:06 PM   #14
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Glad you passed man . I get to go try to pass tomorrow...with no cat....
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Old 01-22-2010, 08:37 PM   #15
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Good luck, that's the one thing they did consistently through all 3 tests, check for a cat. This guy barely cared though. He scanned the barcode on the inside of the door, said I'd pass no problem, and all he had me do was the idle test, no 2500 rpms. Don't care, I have my certificate and can get registered now. GF and I went to the DMV, and in 30 minutes they went from 20-22, and I was #71. **** that.
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Old 01-22-2010, 08:43 PM   #16
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I almost got my 91 to pass w/o cat by running very lean. Hard to do without cat and without EGR.

Not hard to pass at all though if you have a cat, correctly tune for 14.7, set up closed loop, and knock back the timing some. You guys with the MS2's that run sequential should find it even easier.
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