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Running with flatspot around 2500rpm

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Old 12-16-14, 07:47 PM
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imitek

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Running with flatspot around 2500rpm

Light load
Full throttle is fine just when crusing at light loads

Could it be to much overlap ?
Ive tried chaning timing and fueling but no luck any ideas
Idle is sweet
Idleing at 1200rpm
At around 900 it starts to pop and cutout so left it at 1200rpm
Old 12-16-14, 09:36 PM
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depends on AFR.

typically some AFR changes or bucking can occur at changeover if the MS is too high. typical crossover points are around 30-40% duty cycle, if this is where you problem is (doubt it, since you said light load) it would happen at 30-40% injector duty cycle.

what ecu do you have?
Old 12-17-14, 07:38 AM
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imitek

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Motec m2r im on it again tonight ive played with the injection timing fuel where the flat spot is its like a specific load its there il make a vid of it and upload it
Old 12-17-14, 08:11 AM
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save a datalog of when the problem occurs. You may need more timing. Some of those light load areas need 30-40, maybe more degrees of timing.
Old 12-17-14, 08:25 AM
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imitek

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Watch "Afr and the flatspot" on YouTube - https://www.youtube.com/watch?v=tttp6tVBM3E&feature=youtube_gdata_player


Yesterdays test afr
Old 12-17-14, 10:51 AM
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ok, so it's lean. There could be a bunch of reasons for that. Post a datalog. The M2R is the real old Motec one right? That runs in a DOS window? I think I've got the software to look through that, as I've messed with Motec before.
Old 12-17-14, 05:39 PM
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I had a similar problem with my Microwreck Lt16. The AFRs where constant but I had a slight hesitation at 2400. It turned out to be the injection timing table. It went from 150 degrees to 180 degrees right at 2500. You could actually feel it as a slight hesitation no matter the load. The higher the load the more I felt it. I ended up transitioning the values at a higher rpm and much better.
Old 12-17-14, 07:17 PM
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imitek

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ill put my mapp up as may be easyer to see i will get a log in few days this is the only way i could upload file also i thort that was rich for idle low ?
https://www.dropbox.com/s/o9uukderlc...0.bmp.T62?dl=0
thats my most recent few more vids Watch "Part 2" on YouTube
https://www.youtube.com/watch?v=-DBR7ufhGkU&feature=youtube_gdata_player

Watch "Ignittion table" on YouTube
https://www.youtube.com/watch?v=fUJbJWVO6Kk&feature=youtube_gdata_player

Watch "Cold start low load" on YouTube
https://www.youtube.com/watch?v=g5iruOwqtWs&feature=youtube_gdata_player
Old 12-17-14, 07:29 PM
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imitek

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Originally Posted by jmm8904
I had a similar problem with my Microwreck Lt16. The AFRs where constant but I had a slight hesitation at 2400. It turned out to be the injection timing table. It went from 150 degrees to 180 degrees right at 2500. You could actually feel it as a slight hesitation no matter the load. The higher the load the more I felt it. I ended up transitioning the values at a higher rpm and much better.
My injection timing starts from like 220 and from 500rpm upto 200 at 2500rpm then tapers down i will have another play with it
Old 12-19-14, 10:48 AM
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imitek

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log files i got 2
one is engine warm and just flat spot
and the other is log of me changing timing and smoothening it or trying to lol its geting better but that flat spot is still there ive tried going crazy advancing timing jnust to test if it makes any better but not

but any way the files

the short file warmed engine
https://www.dropbox.com/s/hy5r5fh20a...M_RUN.LOG?dl=0

starting from cold and adjusting fueling and timing
https://www.dropbox.com/s/dm1ghg7oyg...NGINE.LOG?dl=0
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