| Author | Message | ||
     Darth_buell |
Searched and searched. Can't find anything on here regarding it. The cover changed on the 08 I believe. Mine is rectangular. Someone point me in a good direction. Just don't have the cash for a manual at this time due to a divorce. | ||
| Ericz |
What are you trying to do? The timing can't be set or adjusted mechanically. The only change you can make is to the ignition maps in the ECM using tuning software. | ||
| Darth_buell |
Something tells me the timing was off. When I got it I'm guessing the guy had an aftermarket exhaust on it and put back the stock. Sometimes it it cranks and then stops then fires up while holding the start button. Other times it stutters when it starts. Others it fires up in a nanosecond. Just noticed that my exhaust cable was broken. Just ordered a new one and wired the valve open for now. Maybe that may have something to do with it. It cuts out sometimes when giving it gas at low RPM's also. Since ECM spy doesn't work in the newer ones, is there some software that works nowadays? | ||
| Froggy |
Like Ericz said the timing can't be mechanically adjusted as it is completely computer controlled.
That is normal, it depends on what stroke the motor stops on after you cut it. If it stops on a compression stroke it takes more effort for the starter to crank it, but if it started on the exhaust stroke the starter will have a chance to spin the flywheel and build up some momentum before hitting the compression stroke. If your heart is set on playing with it anyway, TunerPro RT will let you modify any parameter in the ECM including the ignition system. Rather than futz around with that, I recommend getting the EBR Race ECM for the stock exhaust, it significantly improves the bike beyond just the fuel maps, and may help with the other issues you describe. | ||
| Darth_buell |
Thanks a bunch bud. Pretty soon I'm goin for the Spec Ops pipe with the matching ECM. Already have an extra stock pipe so I won't have any down time. | ||
| Reepicheep |
So that must have changed in 08? Is the crank position sensor now mounted to a fixed position rather than on a plate that can be rotated? One less thing to screw up I suppose, provided you have enough precision in the machining for the cam cover and in the cam position sensor. | ||
| 1313 |
Bill, We don't need no stinkin' cam position sensor...well, at least '08-up XB owners don't:  So that must have changed in 08? What rock do you live under? Seriously, though:  Sorry for busting your chops - I couldn't resist... 1313 | ||
| Ducbsa |
That new crank position sensor must be pretty smart to know that the piston is coming up to to TDC on the compression stroke and not the exhaust stroke. Any hints on how that is done? | ||
| Akbuell |
Duc: Not that I really understand how it all works, the inside edge of the crankshaft flywheels are notched. The crank sensor acts just like the speed sensor, and 'counts' the teeth as they go by. The ECU uses this info to know where the crank is in its rotation. Hope this helps, Dave | ||
| Ducbsa |
I'm still not getting how it knows notch #1 is going by while on the compression stroke or the exhaust stroke, unless the ignition fires at ~36 deg BTDC on both strokes, plenty of engines do. | ||
| Sifo |
unless the ignition fires at ~36 deg BTDC on both strokes, plenty of engines do. That was my first thought when I read your first question. My second thought was that it still needs to know what stroke it's on for the fueling. I don't know how it figures it out though. | ||
| Akbuell |
My XB service manual says the ignition spark is independent per cyl; not a 'waste spark' system. There are 30 teeth cast into the flywheel rim. 2 consecutive teeth are missing, giving the ECM a reference point as to where the crank is in its rotation, and therefore what stroke a cyl is on. Hope this helps, Dave | ||
| Ducbsa |
Wouldn't those two missing teeth come around on every revolution, during the compression stroke and the exhaust stroke and not tell you what stroke the cylinder is on? | ||
| Natexlh1000 |
Hee! good point there. At least with the old method, it was turning at half speed. There is some scary magic trick involved I'm sure. | ||
| Ericz |
The ECM can tell when the crank slows down due to a compression event. With that and knowing where the 2 "missing" teeth are, it can calculate which cylinder to fire. | ||
| Ducbsa |
How does it detect a compression event? Is there something like a knock sensor? Ooops, read that again. Detecting slowing down seems reasonable. With relatively few notches to work with, it must have been difficult to decide on a threshold for the slowdown being a compression stroke. I guess at initial startup, it requires 2 revolutions to decide? (Message edited by ducbsa on September 28, 2013) | ||
| Natexlh1000 |
Mine has always cranked very slowly. (wussy starter? all grounds verified) It will sometimes rotate less than once and fire right up. Almost like I kicked it over with my leg. Anyways, I'm not sure how the computer could tell what jug is under compression in that circumstance. |
