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Old 02-07-2008, 12:58 AM   #1
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Default bucking while shifting (megasquirted)

I finally got my squirted miata up and running. Datalogged a couple of runs to get the afrs legit, but i am having a little problem. The car seems to run good, but when i shift gears(low rpm around town driving) the car seems to buck and bog down. It is more pronounced in the lower gears mainly 1st to 2nd and 2nd to 3rd. Also, when i rev it, it is not that responsive and seems to studder a tad bit. Now granted this is a 93, is it possible that the lack of TPS is the culprit here?
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Old 02-07-2008, 01:04 AM   #2
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Could be. Not a MS expert, just getting my feet wet with it as well. I have the same problem your describing on my 99, and it will do it if it goes rich or lean. Mine was going rich when I revd it, and I adjusted the Accelleration enrichment and got it better, but still needs adjusting. I'm gonna say with my limited knowledge you need a good TPS.
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Old 02-07-2008, 01:22 AM   #3
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I'm gonna say with my limited knowledge you need a good TPS.
thats what i suspected
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Old 02-07-2008, 02:37 AM   #4
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Sounds like the acceleration enrichments are a bit out. Post the datalog so we can see the AFRs.
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Old 02-07-2008, 02:50 AM   #5
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Thats not because of not having a linear TPS signal. You just have to do more tuning. There are many other things to tune other than the VE and Spark tables. Takes a little tinkering with before you get it to run smooth. I got mines running smooth on Mapdot and not the TPS.
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Old 02-07-2008, 10:29 AM   #6
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do you have overrun turned on and good acceleration enrichments? disable the acell enrichments by turning the threshold to 255map. easily rule it out.
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Old 02-07-2008, 11:01 AM   #7
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I assume you checked the grounds? (its my restart the computer theory of MS cars)
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Old 02-07-2008, 10:52 PM   #8
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Im actually trying to help him tune his car and mine is having the same issue as well. He has a begi s and I have a greddy but we have about the same power goals and are running the injectors and engine managment. How do I know what to change in the accel. Wizard to get better throttle response? Should I post a datalog of a few quick throttle blips?
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Old 02-08-2008, 12:24 AM   #9
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Quote:
Originally Posted by MikeRiv87 View Post
Im actually trying to help him tune his car and mine is having the same issue as well. He has a begi s and I have a greddy but we have about the same power goals and are running the injectors and engine managment. How do I know what to change in the accel. Wizard to get better throttle response? Should I post a datalog of a few quick throttle blips?
Yes please. That would help alot. Make it display RPM, MAP, TP, PW at the minimum.
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Old 02-08-2008, 12:34 AM   #10
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Should i post the datalog file or just a snap shot of a throttle blip in mlv?
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Old 02-08-2008, 12:46 AM   #11
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Should i post the datalog file or just a snap shot of a throttle blip in mlv?
Both. You can post screenshots without being a subscriber. But in order to attach files i think you have to be a subscriber. Screenshots will work though use tinypic.com if you need to.
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Old 02-08-2008, 01:08 AM   #12
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ok cool... I try and gets some pics up first thing tomorrow.
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Old 02-08-2008, 01:53 AM   #13
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Is is properly grounded?
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Old 02-08-2008, 02:37 AM   #14
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It is properly grounded and mikeriv is even running the mad tyte jdm engine ground kit(in house modification) and is experiencing similar issues.
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Old 02-08-2008, 09:52 AM   #15
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Quote:
Originally Posted by Braineack View Post
disable the acell enrichments by turning the threshold to 255map. easily rule it out.

good idea!
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Old 02-08-2008, 09:55 AM   #16
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Scott, I turned it to 255 in the accel. Wizard and it seemed to drive slightly better but it seemed to be slower. Does that make any sense?
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Old 02-08-2008, 11:35 AM   #17
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I'd definitely agree this has NOTHING to do with not having a TPS, and everything to do with tuning. I still run the stock TPS on my '91 with no driveability issues, putting down over 250whp. My A/C isn't charged yet since I replaced the compressor, if it was working, I might occasionally stall when I had the AC on... that's the main thing the VTPS will help you fix... And there are workarounds for this without a VTPS.

Tuning! Your VE and Ignition maps need to be spot on before you even bother with AE (Acceleration Enrichment) tuning much, and AE should be left turned off (like Ben directed with MapDot set sky high) while you tune the VE table.

The MegaManual will walk you through tuning AE fairly well-- you'll want a wideband to be able to see if you're too rich or too lean on tip-in. They feel very similar.
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Old 02-10-2008, 08:31 PM   #18
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Ok guys here is a pick from MLV of a couple quick throttle blips. What do you make of it? It seems that it goes rich when i blip the gas. I have ego correction turned off and the mapdot threshold set to 255kpa.

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Old 02-10-2008, 08:39 PM   #19
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It would be much easier to see what's going on with the whole logfile-- I need to be able to load it into MegaLogViewer and scroll through to different positions. Also how do you have your LC-1 configured?
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Old 02-10-2008, 09:01 PM   #20
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lc1 is 0-5v and 10-20 afr. Let me go take another log of just the throttle blips. I should have the ego correction and AE turned off during the datalog correct?
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