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Old 09-25-2010, 01:54 PM   #1
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Default 5000 rpm flat spots

I've been consistently getting a flat spot around 5000 rpm with my car. It will push through and pick up dramaticaly after it but it's right were I end up when changing gear and seems to get worse when I land in it. If I do a wide open throttle run in 2nd and 3rd the car pulls nicely to 5000 then seems to go a bit dead, then pulls strongly to the redline, where I grab the next gear is seems to stick at its revs for a while before pulling strongly again.
I've got EAE switched off and the thresholds for AE are both set at 0 rpm (think this will turn it off). VE analyze live only seems to pull a few points of fuel each time. AFR seems to stay quite stable whilst in boost at 12.5 ish.
I've tried reverting to the starter tune from DIYAutotune and the car didn't want to rev past 5000 with lots of popping and banging.

I'm running a DIYPnp v1.1 and msextra code 3.0.3 t

I've attached my msq and a log of a previous run. Is it just more time required on the fuel table? (my lc-1 does cook itself very quickly when doing WOT runs and I only seem to get one pull to tune on)
Attached Files
File Type: msq CurrentTune.msq (76.8 KB, 49 views)
File Type: msl 2010-09-20_19.34.52.msl (374.5 KB, 71 views)
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Old 09-25-2010, 02:50 PM   #2
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What ignition system do you run? Stock, COPs, other? What plugs?
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Old 09-25-2010, 02:54 PM   #3
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Stock ignition with ngk bkr7e plugs
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Old 09-25-2010, 03:04 PM   #4
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Maybe spark blow out resulting in misfiring...
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Old 09-25-2010, 03:21 PM   #5
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Would closign the gap reduce the chance of spark blowout? If so what sort of gap should I be running? I'm hitting about 9 psi max.
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Old 09-25-2010, 07:08 PM   #6
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What year car do you have? If you are on stock coils I would suggest a gap of .022. Anything over 9psi on my 94 stock system and I would get spark glow out.
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Old 09-26-2010, 05:13 AM   #7
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It's a 96 car. Got a feeling i'm on stock gaps on the plugs. Need to pull them out of the car.
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Old 09-26-2010, 05:42 AM   #8
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Put the latest code 3.0.3u on before you try anything else.
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Old 09-27-2010, 05:13 PM   #9
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Well i've updated to 3.0.3u (hope the next release is a way off as it's hard work getting to those coil plugs ) and gapped the plugs down a bit (I'll get some feeler guages and do it properly soon) and then went for a quick run.

First 2nd gear pull and it baulked at about 5k then again a bit further up the rev range. Second pull it seemed a bit better but when I changed into 3rd it felt pretty dead for a while before picking up again (revs are rising but the push in the back disappears before returning)

I've attached a log of it. No changes from my previous msq.
Attached Files
File Type: msl 303u.msl (492.7 KB, 62 views)
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Old 09-27-2010, 05:32 PM   #10
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increase your MAPdot threshold to 1000.

decrease your MAP factor lag to like 30-20.
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Old 09-27-2010, 05:56 PM   #11
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Sorry but where do i set these?
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Old 09-27-2010, 06:12 PM   #12
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MAPDot threshold is in the AE wizard, MAP lag factor is in 'General, Lags'
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Old 09-27-2010, 06:42 PM   #13
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Thanks. I've set these now but i'm a little confused as to what effect they'd have especialy the MAPDot threshold. My AE is set to 100% tps and the low and high rpm thresholds for ae are both 0 rpm which seems to switch it off.
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Old 09-30-2010, 04:40 PM   #14
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Okay, Map dot threshold is now 1000 and lag factor is 20. Went for another run and am still getting the same flat spots. Ive attached another log. Duty cycle and Pulse width seem to be smoother but you can still see where the revs stop climbing then pick up in the third gear pull at 454 seconds.
Attached Files
File Type: msl 2010-09-30_20.16.10.msl (718.7 KB, 60 views)
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Old 09-30-2010, 05:26 PM   #15
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and you can acutally feel that?
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Old 09-30-2010, 05:45 PM   #16
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There's a definite step in the power delivery where the car goes flat then takes off again
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Old 10-08-2010, 05:00 PM   #17
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Any progress on the flat spot?
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Old 10-09-2010, 04:51 PM   #18
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Spookyfish, no real progress on what's causing it. I've regapped the plugs to 0.6mm from just over 1mm, upgraded the firmware to 3.0.3u and although the cars a bit smoother the flat spot is still there. Thing is as soon as I reset the AE thresholds and turn EAE back on the car pulls smoothly throughout the rev range and I get none of the flat spots. I'm left wondering what the enrichments are covering up.

I've attached before and after enrichment logs if anyone can spot what it's doing and changing. Thanks
Attached Files
File Type: msl 2010-10-04_19.45.16.msl (158.6 KB, 60 views)
File Type: msl 2010-10-04_19.50.07.msl (405.3 KB, 51 views)
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Old 04-19-2011, 04:49 AM   #19
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Quote:
Originally Posted by GrahamA View Post
Spookyfish, no real progress on what's causing it. I've regapped the plugs to 0.6mm from just over 1mm, upgraded the firmware to 3.0.3u and although the cars a bit smoother the flat spot is still there. Thing is as soon as I reset the AE thresholds and turn EAE back on the car pulls smoothly throughout the rev range and I get none of the flat spots. I'm left wondering what the enrichments are covering up.

I've attached before and after enrichment logs if anyone can spot what it's doing and changing. Thanks

Did you get anywhere with this?
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Old 04-19-2011, 02:16 PM   #20
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Finaly think i've cracked this. Was studying the logs from several runs and could see that the spark advance dropped off then rose back up in time with the way the power was dropping then coming back in.

The original timing map was a copy from a guy with a similar setup but with a 99 head. I've got a timing map from another bloke running the sam esetup but with 10 psi rather than 8 and there's an immediate improvement. Got to sort the fueling now and my lc-1 keeps erroring with this map (either lean or rich for the timing making my egt's rise)
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