|Posted on Monday, May 09, 2011 - 12:51 pm: ||
I've dug through as many posts as my Google search can come up with, but can't find the answer to my Buell's problem... please help!
Coming out of winter I decided to install a Jardine exhaust, K&N filter, race map (via ECMspy) and change the oil on my 2004 XB12S. My bike also has the breather re-route modification, which I did last year.
All of the physical work went OK. The bike started up and I drove it several times - it sounded good and ran well. However, after a few rides I noticed that the bike wanted to stall on the first and maybe second start-up. The idle was a little low so I bumped it up with the idle adjust. The bike started better but on my ride home the next day the idle hung high when I throttled down with the clutch in coming off the freeway.
I was able to coax the idle down each time it happened and managed to get home OK. It seemed like it was time for a TPS reset, so I did it that evening. When I came out to ride the bike the next morning it would turn over but not idle. That was about three weeks ago and I still can't get the bike to run.
What I've tried (nothing has fixed the problem):
Plugs - after the TPS reset and trying to get the bike to run it smelled very rich and both plugs were fouled when I pulled them. The AFV was only 105 after my hardware/eeprom change over, but of course it's still running open loop with cold start enrichment during the initial startup. I've lowered the cold start enrichment but it seems hardwired at 160% for the initial value, regardless of what I program (130% is what I've set for the coldest start) – it does drop from 160% while it briefly idles, but still always starts there. I changed the plugs (replaced with the HD brand) and it still won't run. I’ve pulled the front plug a few times during diagnosis after tying multiple starts and it comes out wet/black-ish. I’ve checked the gapping of the new plugs multiple times.
Wires/coil – I pulled the plug wires and ignition module. All parts have good resistance values. No obvious shorting paths/carbon tracks.
Timing – is OK.
Air – I’ve pulled the air box just in case there was any chance it was choking off (or had a mouse nest etc). Also vented my breather re-route directly to the breather valves in case there was some kind of clog.
Fuel – I garage my bike but didn’t add stabilizer for the 5 months of winter storage… when it was running I topped the bike off with about 1.5 gallons of 93 octane. Just this week I added a fuel cleaner called Sea Foam that’s supposed to be really good. It hasn’t run since trying this but I honestly haven’t pulled or cleaned the plugs again which are likely fowling from all the idle attempts. I’ve also tried to run with the gas cap not fully installed in case there was an issue with the vapor vent.
Oil – the oil level appears good when cold. Certainly not over filled.
Voltage – the battery voltage and alternator function seem OK based on the battery voltage read before starting and while the bike idles for less than a minute before stalling.
What I haven’t tried but am sure will be recommended:
1) Completely changing out the fuel.
2) Changing out the spark plugs again and/or replacing with the NGK recommendation.
3) Cylinder compression test.
4) Intake gasket leak – or any other gaskets for that matter.
5) Messing with the fuel map. I burned an 04 race map which is suitable for my bike and the bike ran for a few days before behaving like this…
Since doing whatever I’ve done the bike does seem to at least want to try and idle. It starts up as if everything is fine – it idles fairly consistently for maybe 20-40 seconds then the RPM’s just drop and it stalls.
Getting really frustrated… winter in New England will be here again too soon!
Please help if you can and thanks much!
|Posted on Monday, May 09, 2011 - 07:53 pm: ||
You really need to take the bike out on the open road and run it at constant rpms at approx 60 mph for 4 to 5 minutes in order to let the ECM learn its new environment with new components, etc. After doing this, it should run normally assuming that you performed a proper TPS Zero Reset procedure prior to taking off on this road trip and there are no other sensor anomalies.
|Posted on Tuesday, May 10, 2011 - 02:11 pm: ||
@Sparky: I would love to take the bike out and let the ECM do it's thing - but the bike won't even idle. It idles for maybe 30 seconds like everything is fine and then the RPM's just drop and it stalls. I can't coax it to idle by manually adjusting the throttle either - that just makes it stall sooner.
|Posted on Wednesday, May 11, 2011 - 01:15 pm: ||
Check your cam position sensor. When mine failed it gave too many sparks per revolution and would run just a few seconds at a time. If you raise the rear wheel and remove the plugs, the engine can be rotated in high gear. Watch the plugs to see if there is one fat blue spark per revolution or not.
|Posted on Wednesday, May 11, 2011 - 05:24 pm: ||
@Harleyelf: That's a great suggestion. I posted separately about the CAM position sensor behavior about a week ago because I see multiple sensor transitions on ECMSpy for one revolution of the CAM, but more digging in the manual found that should be the case (6 full sensor transitions per cam rotation). However, what bugs me is that the fuel pump goes off for every transition which makes me think the spark would try to ignite multiple times per cam rotation too - that would clearly be WAY wrong.
|Posted on Wednesday, May 11, 2011 - 05:29 pm: ||
@Harleyelf: also - was your solution to just replace the CAM position sensor or was it more involved?
|Posted on Thursday, May 12, 2011 - 12:52 am: ||
I didn't get to the cam position sensor until after I had removed the fuel injection. It runs better than new with my 60 year old SU. Perhaps the six transitions are not all creating sparks until the ECM is old. I have a Sportster ECM and VOES, and went to dual fire coils with the dual fire ECM.