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Old 03-07-2010, 07:24 PM   #1
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Default Sputter and MS disconnects

Just as the title says, when entering boost around 3.5kish rpm, it sputters a bunch, and if I'm datalogging, the MS apparently disconnects. Unless I drive so the problem doesn't occur, which wouldn't be helpful, this is the longest log I can get, sorry. All I can see is the MAT jumping all over the place, but I realized that's between 61 and 62 degrees. Tell me what you guys think. I'm too groggy from a long weekend of doing nothing for my super-duper-diagnostic skills to come up with any possible solutions.

Recently I rewired my fans, including bundling in the MAT wiring with the fan wiring (across the top of the radiator, so the fans don't eat it), replaced my PCV valve, changed oil/filter, and it's sat for a couple weeks. Before that it seemed to run fine.
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File Type: msl 2010-03-07_14.52.10.msl (8.2 KB, 76 views)
File Type: msl 2010-03-07_14.57.50.msl (55.4 KB, 59 views)
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Old 03-07-2010, 07:54 PM   #2
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Actually, it would be great if you could email me a log with the problem happening, a log without the problem happening, and your most recent msq. I'll look for the obvious. [email protected]
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Old 03-07-2010, 08:00 PM   #3
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I can get you the first and last, but a log without it happening probably won't happen, unless you want one with me staying out of boost? Won't be too hard, I can do it up and down the street (~1 mile) if that's good enough. I could also easily disconnect the waste gate and see if it's happening at upper rpms regardless of boost. Email coming your way though.
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Old 03-08-2010, 01:12 PM   #4
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I'm not too crazy about your a/f targets, and you're lean in boost.

What do your plugs look like? What are the plug gaps?
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Old 03-08-2010, 01:37 PM   #5
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Afr target table was stolen from an old thread on here, from Joe perez actually. Do you have a better target table I could try? I'll check the plugs when I get home, I'm assuming after another test drive? Gaps are .035" I think, and I have Toyota cops btw, didn't realize that wasn't in my sig.

I never liked the table, as JP's boost was higher than mine, so pressures he was boosting right through momentarily are where I'm staying (11psi)
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Old 03-08-2010, 01:41 PM   #6
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here's what I use when running 12psi.

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Old 03-08-2010, 08:14 PM   #7
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Yes we know, you have a MSII. Thanks for sharing. Do you happen to have a 8x8 table? I think my main issue is I haven't touched the axis scaling at all. I have a "0" line.

I'll pick out the lines I need, obviously 200, but tell me which 8 rpms and pressure columns/rows I should use off that table. Please.

And I'm going to go check my plugs. I just realized I have forgotten to grind down the plastic ring on my cops, is it that important? Does it make them sit too high? With all the issues I've been having I had forgotten I wanted to do that, but I did have a week or two in there where it seemed to be running great.
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Old 03-08-2010, 11:58 PM   #8
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just scale the same numbers for 8x8...
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Old 03-09-2010, 12:38 AM   #9
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Ok, I scaled numbers and came up with this. Am I trying too hard? Should I honestly just delete every other column/row until I have an 8x8 table?
Name:  afrtargettable2.jpg
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Old 03-09-2010, 03:03 AM   #10
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Looks o.k. to me
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Old 03-09-2010, 08:53 AM   #11
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I should add that I bolted the cops a little closer to the valve cover yesterday and the sputters seemed to cut in half and I gained a little throttle response. Could have been completely unrelated, but I want to blame my cops. Running lean wouldn't shut off the MS and therefore datalogging, would it?
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Old 03-09-2010, 11:23 AM   #12
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Quote:
Originally Posted by curly View Post
Running lean wouldn't shut off the MS and therefore datalogging, would it?
Nope. I once got a MS'ed car to cruise at around 18.0:1. Didn't have issues with that AFR on that particular engine.
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Old 03-09-2010, 03:57 PM   #13
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What would cause this? Plugs will hopefully be checked today, if all the snow melts (65* and sunny last Saturday?!?)

i'm paranoid about my head gasket, as I was not satisfied with my install of it a few months ago, despite it running fine for a month or two. I noticed some water vapor on the bottom of the oil cap (white foamy residue) and started panicing because of that. This was right after my first post-hg replacement oil change, and my friend said not to worry
as it was most likely left over water in the oil system breaking loose and burning off after
the oil change.

Would a little coolant in the combustion chamber cause a high rpm sputter?
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Old 03-09-2010, 09:58 PM   #14
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Well, updated my afr target and adjusted plug gap from .040-.042 to .030 and it pulls like a freight train! Looks like the target table was all I needed!

new .msq and data log attached.
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File Type: msl 2010-03-09_17.29.16.msl (279.6 KB, 67 views)
File Type: msq 460s!.msq (32.8 KB, 74 views)
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Old 03-10-2010, 10:48 AM   #15
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I'm not sure what you're asking for, or what the problem is?
You say you sputter "when entering boost around 3.5kish rpm". But you're entering boost around 2k rpm--and you're totally too lean when tipping into boost. Maybe that's what you're feeling. I don't see any problems around 3500 rpm, and I see that you're running ~12 psi max boost.
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Old 03-10-2010, 01:29 PM   #16
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Misfires can trigger electrical noise, and electrical noise can trigger all sorts of weirdness.
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Old 03-10-2010, 01:59 PM   #17
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Sputtering all the way up to redline, not just when entering boost. I was trying to say it acts normal until then. "sputtering" meant it felt like someone was rapidly switching a few coils on/off. I guess momentary misfires would be a better word. But like I said the smaller plug gap seems to of fixed it, but Casey reminded me that .041" should be acceptable with cops. My running dwell is at 3.0. How do I go about tuning the lean spikes out? Cause I've never liked it either.
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Old 03-10-2010, 02:51 PM   #18
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What COPs are you running? It's tough to set dwell on them without a scope.

.041" may be too much gap. Try bringing it down and seeing if the misses go away.

You may be a bit lean in boost because your old AFR target table was lean. You'll want to add some fuel.
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Old 03-10-2010, 03:45 PM   #19
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Check post #14 in this thread, I attached my new .msq and datalog, which I can email to you if you'd like. Sputter is gone with .030" gap. I'm also running a new target table, which is shown in post #9. Cops are from a '01 Toyota corolla if I remember correctly. Is 3.0 running dwell good for this? Again I can email you the new msq and datalog if you'd like.
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Old 03-10-2010, 03:50 PM   #20
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Yeah I saw your log. Your new target table looks better, but you're still lean getting into boost. You are fat at higher boost, but you were a bit too lean for comfort down low. Needs a bit more tuning.

The Toyo coils are hotter than the stock set up, but IMO still leave a lot on the table. Actually, the stock 1.6 coils don't seem to be bad, it's the ignitor that's weak.
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