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Author Topic: Siemens 630cc injector misfires  (Read 19887 times)
Jason
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Breaks everything!


« Reply #15 on: February 01, 2012, 09:10:11 AM »

I just confirmed I was using stock KFMRES...  You can try bumping up KFMRES to dial out the occasional misfire.
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Roman (RSKelme)
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« Reply #16 on: February 09, 2012, 10:03:50 AM »

With KRKTE set to 0.03508 and essentially stock TVUB values my LTFTs look pretty good.  I'm going to keep checking them but they eventually get down to less than 1%.  I was still getting 100+ misfires on cylinder 4 still so I copied over the KFMRES and KFMRESK values from the NefMoto v1.2 tune.  That nearly eliminated all of the misfires!  After the car was warmed up it idled with no misfires.  I'll monitor that as well and think about bumping up the idle to 800 or so as that is where it seems to want to sit. 

Are there negatives to using KFMRES and KFMRESK values further from stock?  I can try bringing them closer stock and find the sweet spot but it idles nice right now.

Thanks for the help!  Next step is installing the 85mm MAF and adjusting accordingly.
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nyet
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« Reply #17 on: February 09, 2012, 12:02:48 PM »

Page 52 from Greg Banish's book: Designing and Tuning High Performance Fuel Injected Systems states that;

 "At idle it is helpful to maintain a torque reserve to ensure that the engine can quickly respond to changes in resistance. By intentionally operating the engine with less than MBT timing, the ECU knows that it could increase the engines torque almost instantaneously by adjusting back toward MBT. The ECU can also instantantaneously retard timing to reduce engine torque in cases where less is needed for a brief period.. The gap between delivered ignition timing and actual MBT at idle represents the torque reserve that is held for unforseen changes in engine loading later on"

AH. And to maintain the same rpm with more reserve (worse timing), the throttle plate is open a bit more, at the cost of a touch of fuel efficiency to keep lambda 1?

Thanks, finally I understand torque reserve.
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ME7.1 tuning guide
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Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
cactusgreens4
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« Reply #18 on: February 09, 2012, 01:15:11 PM »

What are you guys using to detect misfires and read your ltft and stft. Before I just used an OBDII scanner but I do not own one and have not had to use the one at the auto part store since the nefmoto software came out but I dont think I can use that for reading the fuel trims. Or can I?
Thanks
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Roman (RSKelme)
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« Reply #19 on: February 09, 2012, 01:35:04 PM »

What are you guys using to detect misfires and read your ltft and stft. Before I just used an OBDII scanner but I do not own one and have not had to use the one at the auto part store since the nefmoto software came out but I dont think I can use that for reading the fuel trims. Or can I?
Thanks

I'm using VAG-COM to monitor LTFT (block 32) and misfires (blocks 14-16).  I'm not sure if the NefMoto software can be used to monitor.  I forget the name of it (ME7 Logger?) but there is a high sample rate logging tool someone developed and posted here.  I believe that could be used though I haven't tried it.        When it comes time to serious logging I'll probably use ECUx if only because I already have it setup and I'm familiar with it.
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carlossus
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Leon Curpa Stg1+


« Reply #20 on: February 09, 2012, 01:42:25 PM »

Take the time to configure and use ME7Logger guys. It's the kitten's pyjamas.

http://www.nefariousmotorsports.com/wiki/index.php/Main_Page#Software_Tools

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rob.mwpropane
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« Reply #21 on: February 09, 2012, 04:32:24 PM »

AH. And to maintain the same rpm with more reserve (worse timing), the throttle plate is open a bit more, at the cost of a touch of fuel efficiency to keep lambda 1?

Thanks, finally I understand torque reserve.

That's what I assume, and your welcome.

As far as EcuX, put it in the recycle bin and move on. Me7logger with the GUI is too easy to use. I=retard when it comes to computers. I got it working without a hitch, and that means its really, really easy.
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This has nothing to do with cars but you can see my glorifying job at,

www.MWPropane.com
Roman (RSKelme)
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« Reply #22 on: February 09, 2012, 04:39:45 PM »

Take the time to configure and use ME7Logger guys. It's the kitten's pyjamas.

http://www.nefariousmotorsports.com/wiki/index.php/Main_Page#Software_Tools
As far as EcuX, put it in the recycle bin and move on. Me7logger with the GUI is too easy to use. I=retard when it comes to computers. I got it working without a hitch, and that means its really, really easy.

Ok, Ok... I'll check it out  Smiley
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