I have been trying to get a single cylinder set up with my micro V3.770, and have spent many hours getting it to start decent. Once started, it runs good, at least in neutral, up to my red line of 5200rpm. The problem is that the thing has very erratic spark timing when cranking, usually way too advanced, it fires out the throttle and backfire out the exhaust, and now has broken a couple hundred dollar starter drive from "kicking back". Now I need advise, it's getting too expensive. It is tough to get started, because of the random timing, "usually way too advanced", but when it does start, it runs great, althoug the timing is almost always off by 15 degree increments, one time it's 15 off, next time 30, next time 40 something, next time retarded 15 or 30..... Seems to be 15 degree steps for some reason. It syncs (3) right away on the input/output "black screen", but will show a quick re-sync when it kicks back, and will get always a negative "trigger fix" count down. ( the more kick backs the more count) chicken or the egg? I am running M-0 with CRANK sync. It has a 75 tooth ring gear, and useing the origional CDI trigger hump, (which I milled down to the with of the origional vr sensor. (origional hump was very wide) I'd have to say the sync signal is still about twice as wide as the ringgear waveform. Although they both have very nice "sawtooth" waveforms. Could this be a problem? Dont know where the processor sees the trigger point on an AC signal. They are both very strong amplitude when cranking, which is about 450-650 rpms even. I changed the crank RPM setpoint to 750. Funny thing is, sometimes the spark advance gage bounces around, pegging out or reversing into neg when its throwing its cranking timing fits. I used the Auto trigger mode, and even tried just distributer mode(but couldnt even get that to throw a spark) My trigger offset is like 330 to 285, (depending on where it decides to pick TDC. (I changed the trigger offset to get timing back inline, only to see its off after shutting it off and starting again) Sometimes, like one in 10, it will fire right up with out any fuss, but the timing will usuall be off again.
Ive tried adjusting almost everything I could think off, but never changes anything for the better. Is there a setting somewhere that may help? I don't believe there is a signal problem, can the processor under stand 75 teeth "odd number" even though it is a one cylinder, LS-2 COP waste fire engine? I don't think it shoud matter, as it is really running as a one cylinder 2 cycle. Should I chose 2 cycle in the settings for engine setup? I have selected IGN tied together, and used the diodes and resistor to ground (or gate?) on the outputs.
Ive tried swapping the two leads on both the VRs, and didn't change anything.
I know there are many many settings, and cant tell you how, what and when I did, in 5 sheets of paper, but am looking for some insight on this... It;s just to painfull to hear that engine kick back, pop and backfire like that, wondering whats going to break next....
single cylinder, waste spark, random sync and ignition timin
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Re: single cylinder, waste spark, random sync and ignition t
I have never heard of the random timing. All I can think of is that the Pulse tolerances aren't working. What can happen is that during cranking the flywheel jerks a lot more on a small, 1 or 2 cyl engine than on a large many cylinder engine. So you have to allow large tolerances, but if there is any noise, this can cause the tooth count to go off and the timing follows. Eventually it catches up, but evidently not quick enough in your case. Another possibility is wrong configuration of the starting mode - with 75 teeth you should be able to start with calculated cranking trigger. Another possibility is the sync tooth is either noisy or can get out of alignment with the flywheel teeth - not possible if the sync tooth is built into the flywheel.
To go any further we need to see your msq and a short datalog of a start up. You should make the msq either just before or after the datalog. The trigger counting down happens when it fails to detect a tooth within a tolerance of where it should be, based on the last time between teeth - as opposed to detecting too many teeth due to noise.
To go any further we need to see your msq and a short datalog of a start up. You should make the msq either just before or after the datalog. The trigger counting down happens when it fails to detect a tooth within a tolerance of where it should be, based on the last time between teeth - as opposed to detecting too many teeth due to noise.
Re: single cylinder, waste spark, random sync and ignition t
OK,thanks, I will try to figure out how to get a post of the msq, and a data log of a start attempt, hopefully in next few days, FYI, origionally the next pulse tolerance was 80%, moved it down to 20%, and as with every adjustment made, it starts great the first time after an adjustment, only to find it's back to the same old thing the next start. I didn't mention that the first time I had it going, I was to the point of adjusting the trigger offset, and when I hit "burn", the engine stalled, and cycling fuelpump was the result, and a dead computer, thought I made a huge mistake, but didn't see "red", so whatever, I re-loaded the firmware. I don't remember the starting problem before this, but could be my bad memory, or coincidence. I will get the logs ASAP, and will re-scope my inputs, but am sure they are OK. Also I had changed from "trigger rise" to "calculated", which as mentioned above, helped the first start only after the change. How large of a pulse tolerance should I go? Only thing I didnt change was Tach sig masking; 2ms, 10% Thanks for any input!
Re: single cylinder, waste spark, random sync and ignition t
Ok, I have my msq file here, I try to attach it, and a short log of a crank, not very long, as I couldnt figure how to capture more than a couple seconds worth...? in the little time I had this evening.
I will say, that I grounded out the sparkplug wire during the test,as it is just too risky to crank it with all the randomn timing. We changed the crank pulse tolerance up to 150%, and again as always worked great for the first crank, and then, (drum roll please...) a second time! (as viewed with the timing light) but alas, it was back to the normal timing all over the place, every time after that almost, 15,30, 45 and 180 degree increments it appears to be off, some times right on, I have noticed that with a plug in it or not, it always syncs up instantly, and never shows a trigger fix, untill it revs down when letting off the starter,(probabally normal,negative 1 or 2 counts) its just the timing is always off every next start. My theory is it resyncs and throws the negative trigger fix cause of the extrememy miss-timed spark, causing a kickback, practically stopping the crank in an instant, not because it is missing any teeth. I could be wronge, but I am convinced its the wronge timing causing the re-syncs. But why so far off? and why in random 15 degree multiples?
I will say, that I grounded out the sparkplug wire during the test,as it is just too risky to crank it with all the randomn timing. We changed the crank pulse tolerance up to 150%, and again as always worked great for the first crank, and then, (drum roll please...) a second time! (as viewed with the timing light) but alas, it was back to the normal timing all over the place, every time after that almost, 15,30, 45 and 180 degree increments it appears to be off, some times right on, I have noticed that with a plug in it or not, it always syncs up instantly, and never shows a trigger fix, untill it revs down when letting off the starter,(probabally normal,negative 1 or 2 counts) its just the timing is always off every next start. My theory is it resyncs and throws the negative trigger fix cause of the extrememy miss-timed spark, causing a kickback, practically stopping the crank in an instant, not because it is missing any teeth. I could be wronge, but I am convinced its the wronge timing causing the re-syncs. But why so far off? and why in random 15 degree multiples?
- Attachments
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- CurrentTune.msq
- tuner settings
- (27.45 KiB) Downloaded 67 times
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- ranger crank 3.msl
- crank log, secondary shorted to ground
- (31.5 KiB) Downloaded 64 times
Re: single cylinder, waste spark, random sync and ignition t
I will try the msq when I get a chance, sometime this weekend. But I noticed the msq has 85 teeth, but you said you had 75 teeth ? Also, is this engine a 2 or 4 stroke ?
Re: single cylinder, waste spark, random sync and ignition t
Yeah, my bad, either miss-typed or thought wrong, but it is 85 teeth, and it is a 4 cycle, single cylinder, 500cc in a polaris Ranger.
FYI, I have spent way too many hours on trying to get it to work, and narrowed it down to that it will get sync instantly, and keep it, as long as it doesn't kick back from horribly miss-timed spark, but it just can't pick TDC correctly most of the time. I tried to go the old, non-auto-trigger route even, and then it wouldn't even throw a spark, or sync-up. I dumped the whole project msq, re-loaded the s-19 several times, and re-loaded the ini several times, always with the same result.
It would be interesting to see someone else get it to work, I don't know what I missed, but after a broken starter drive, and a mangled flywheel keyway, (which was not contributing to the problem), I am in the process of trying a 4-x and a cam sync. If that doesnt work, I will have to bite the bullet and try to wedge an M-N wheel in there somewhere.
I greatly appreciate any advise, as I can always go back to the M-O crank sync very easily, (which worked awsome, if it would just get TDC right al the time) I still have lots of fab work to do for any other trigger setup anyway.
FYI, I have spent way too many hours on trying to get it to work, and narrowed it down to that it will get sync instantly, and keep it, as long as it doesn't kick back from horribly miss-timed spark, but it just can't pick TDC correctly most of the time. I tried to go the old, non-auto-trigger route even, and then it wouldn't even throw a spark, or sync-up. I dumped the whole project msq, re-loaded the s-19 several times, and re-loaded the ini several times, always with the same result.
It would be interesting to see someone else get it to work, I don't know what I missed, but after a broken starter drive, and a mangled flywheel keyway, (which was not contributing to the problem), I am in the process of trying a 4-x and a cam sync. If that doesnt work, I will have to bite the bullet and try to wedge an M-N wheel in there somewhere.
I greatly appreciate any advise, as I can always go back to the M-O crank sync very easily, (which worked awsome, if it would just get TDC right al the time) I still have lots of fab work to do for any other trigger setup anyway.
Re: single cylinder, waste spark, random sync and ignition t
I ran your setup and found there is apparently a problem in the code for this setup. The crank synch + flywheel (M - 0) mode does not work correctly in the latest version. It does exactly as you said - it syncs at semi-random times. I will fix this in the next few days.
Re: single cylinder, waste spark, random sync and ignition t
Thanks Grippo! That was my gut feeling after a while, but I didn't want to question a programmers work. I can now quit beating this dead horse. Let me know ASAP, and what to do, (new ini, msq, or s19 or whatever) This is my snow plow rig, and have been blessed with no snow so far, but surely the snow is coming. I plan to keep the M-0 set up if it can work.
Re: single cylinder, waste spark, random sync and ignition t
When I really got into the code I found that it was correct. What was happening was my crummy signal generator setup was the problem. At power startup the signals are erratic, and this, combined with the M-0 mode, which is much looser than the missing teeth mode, allowed sync to occur and stay synched. However when I switched to cycling the connection between the signal generator and ecu rather than cycling power on the sig generator, the signal output stayed cleaned and the spark timing remained the same each time I cycled.
Thinking about it, I found some configuration parameters that may help. The most important of these is to set Cam_Tooth(also Crank_Tooth in the mode you are using) to 85, because the crank sync must, by definition of tooth 1, come in between tooth 85 and tooth 1. Setting it this way it will throw out anything that comes in on any teeth except between 85 and 1. This won't apply on the first rev, because the ecu doesn't know how to number the teeth, but for whatever reason it eliminated the problem on my setup. When I went back to cycling power on the signal generator, with these settings, the spark timing stayed rock solid. I would also reduce the Cranking Pulse Tolerance back to 75% - this may sometimes delay starting a bit, but should make it less likely to give a false start.
Meanwhile I will think about how to make the software more robust in this mode. One way is to inhibit firing until you get 2 confirmed syncs, but this delays startup by one rev.
Thinking about it, I found some configuration parameters that may help. The most important of these is to set Cam_Tooth(also Crank_Tooth in the mode you are using) to 85, because the crank sync must, by definition of tooth 1, come in between tooth 85 and tooth 1. Setting it this way it will throw out anything that comes in on any teeth except between 85 and 1. This won't apply on the first rev, because the ecu doesn't know how to number the teeth, but for whatever reason it eliminated the problem on my setup. When I went back to cycling power on the signal generator, with these settings, the spark timing stayed rock solid. I would also reduce the Cranking Pulse Tolerance back to 75% - this may sometimes delay starting a bit, but should make it less likely to give a false start.
Meanwhile I will think about how to make the software more robust in this mode. One way is to inhibit firing until you get 2 confirmed syncs, but this delays startup by one rev.
Re: single cylinder, waste spark, random sync and ignition t
Ok, so I'll change the "cam tooth" to 85, which I am pretty sure I didn't try, as I was unsure weather they meant "number of cam teeth", or "number 1,2,3,4....tooth. Even though it said it should be "0". I already have turned down the crank pulse tolerance since then. I will try this in next few days, I have to patch a few things back up first, and let you know what happens.
One other question; would the phaseing of the sync signal be real critical? As the 85 teeth spacing dont give a lot of room to "eyeball" the signal to fall in between the small teeth gaps, without scopeing both signals. I can move the sync sensor a little back and forth with some engine dissassembly, but just wondering what is considered ideal to prevent re-syncs,( such as rising voltage as the other is falling, as seen on a scope screen),even though it never seemed to re-sync when I did get it to run as current setup.
One other question; would the phaseing of the sync signal be real critical? As the 85 teeth spacing dont give a lot of room to "eyeball" the signal to fall in between the small teeth gaps, without scopeing both signals. I can move the sync sensor a little back and forth with some engine dissassembly, but just wondering what is considered ideal to prevent re-syncs,( such as rising voltage as the other is falling, as seen on a scope screen),even though it never seemed to re-sync when I did get it to run as current setup.