BMW Airhead "Kompressor" Reborn

Sluggy
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Re: BMW Airhead "Kompressor" Reborn

Post by Sluggy »

I'm not sure this would affect it with one of two injectors sticking, but I had this problem on the bench once. See the red highlighted information at the bottom of the page...

http://www.megamanual.com/ms2/injectortest.htm

Otherwise, I am no expert, but if you post or private message your .msq file, maybe fresh eyes can see something you may have missed.

Sluggy!
R100RT
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Re: BMW Airhead "Kompressor" Reborn

Post by R100RT »

Thanks for the reference, I had seen that this morning and will probably try it tonight.
Going back into the injector test mode causes some concern, I don't want to loose the other fet if one is already gone. Suppose I can replicate the test with the injector fuses pulled, so as to minimize any duress to the M.S. if that was what happened. Otherwise I"m inclined to run both injectors off the one circuit, high impedance and I gather that would be an easy load.
R100RT
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Re: BMW Airhead "Kompressor" Reborn

Post by R100RT »

So, the module does seem to have a failed injector driver (on just the side that was holding that injector open). I have ordered a spare module to have with the bike should something nasty ever occur while on a long trip, and once it arrives will send this ailing unit in for some TLC. Till then, I'm running both injectors from the same remaining driver.
Last edited by R100RT on Wed Aug 15, 2012 5:22 am, edited 1 time in total.
R100RT
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Re: BMW Airhead "Kompressor" Reborn

Post by R100RT »

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guest
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Re: BMW Airhead "Kompressor" Reborn

Post by guest »

Excellent news buddy, like I said it can only get better (guest = 24c when I can remember my password). I found on my bike the WUE didn't follow the default car settings, which are over enriched. I would think your air cooled lump will warm up quicker.
R100RT
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Re: BMW Airhead "Kompressor" Reborn

Post by R100RT »

I thought that was you.
I'd like to say I'm being cautiously optomistic when I am observing repetative results, as last seasons tuning work was a wash based on the fuel pressure problems that went lurking unbeknownst and skewed things badly.
Something else you may have knowledge on, the injector timing setting for me, doesn't seem to yeild any obvious improvements, beyond the default 0 setting where I have left it.
I am basing that on how the engine sounds, and ultimately reacts (not entirely scientific with instrumentation to back up). With "simultaneous" on the two injectors, 1 injection per cycle, it might not be that critical? Perhaps some data logs might give visual indication of better running - could do that?
I have a gut feeling there may be improvements to be had there tho. Can you comment?
Cheers,
Lorne.
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Re: BMW Airhead "Kompressor" Reborn

Post by guest »

I have tried "simultaneous" and "alternate", and using MSExtra, the engine revved/sounded better & there was less smell of fuel on alternate. I am firing 1&4, 3&2 on a four cylinder. Incidentally my engine originally fired sequential 1, 3, 4, & 2 injectors, but on acceleration it became simultaneous on all 4! I think once you get the module fixed alternate will work better for you, but at the moment for a twin, simultaneous should be OK. At least you are injecting the same amount of fuel, from the one good driver :lol:
I have just got my Thunderace engine running and it has a "lumpy" odd sounding idle. I will be playing with the injection timing to see if I can affect things..."Start of Pulse", "Mid Pulse", End of Pulse", maybe even play with the Semi Sequential table, to see if I can affect things, but first I must verify my "#1 offset degrees" through the very small inspection window on the Yamaha engines I am using.

Little bit of video, with the odd sounding idle... http://gallery.me.com/mike.crane/100074 You'll need Quicktime or .mov reader I think.
R100RT
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Re: BMW Airhead "Kompressor" Reborn

Post by R100RT »

That is an odd loap, like half the cylinders are a little lighter on fuel than the other. I'm unable to offer any thoughts, my vantage point is skewed with 2 cylinder behaviour.
I may be rushing the injector timing thing, will let everything else progress as it will I guess.
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Re: BMW Airhead "Kompressor" Reborn

Post by R100RT »

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Last edited by R100RT on Wed Aug 15, 2012 5:23 am, edited 1 time in total.
R100RT
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Re: BMW Airhead "Kompressor" Reborn

Post by R100RT »

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Last edited by R100RT on Fri Feb 03, 2017 12:45 pm, edited 1 time in total.
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