| Author | Message | ||
     Rkutzner |
I pulled out from the gas station this morning (70 degrees out) and after accelerating into traffic the bike started bucking wildly at all rpms and wanted to stall at idle. In traffic I just couldn't safely ride it so I exercised AAA for the first time in many years. Last week in hot (90s) traffic it started acting up (milder surging) but cleared up when I got moving on the back roads again so I chalked that one up to possible vapor lock. So now I'm thinking maybe this is a symptom of the feul pump wire problem ? Any other ideas ? This has come out of the blue and my last TPS reset was ~3000 miles ago. | ||
| Jraice |
What year? Had similar problems on my 09 but the way they protect the wiring on it there is no chaffing... I am still debating whether to replace fuel pump with fresh filters (and risk getting stranded again if it doesn't work) or spring for a new one. | ||
| Rkutzner |
I'm sorry, 2007 XB12STT. I thought I had a signature block there ! I'm just stumped right now because I haven't had enough problems to diagnose a pattern but I also can't just go riding around waiting for it to happen, especially at 0510 in the morning heading to work about 45 minutes away. | ||
| Glitch |
When mine did that, I found that my ECM had broken some of the connections. It was on again off again. Took forever to find it too. Best test is to replace the ECM with a known good one and see if that does the trick. | ||
| Jraice |
Hmm... interesting. If mine continues to have problems I may swap out my race ECM for the OEM unit. Any way to visually see the damage, or to prevent it on the swapped unit? Perhaps its time to swap the race ECM for a custom map on the OEM unit  . | ||
| Rkutzner |
My research is finding the following and pointing more towards an electrical problem: shorted ETS sensor (actually don't remember hearing my fan come on lately) Battery terminals check 77 connector (which I upgraded years ago) check ECM pins check cam timing sensor | ||
| Iamarchangel |
Check to make sure that the throttle body is tight to the cylinder head. It's hard to do but there can be enough of a gap to cause this kind of issue especially since you're thinking it's progressive. | ||
| Skully |
I had a similar problem. I checked connections, found and repaired chaffed wires, replaced the ECM, replaced the CHT sensor, replaced the CPS sensor, and finally found the problem: the TPS wiring was shorting against the intake manifold to rear cylinder head bolts. For some reason it got worse as ambient temps increased. Hope this helps, Keith | ||
| Rkutzner |
I'm going to avoid just replacing sensors before troubleshooting. I think my first test will be to start it up connected to the software and look at whatever it tells me. I suspect it will run good until the 02's are heated up and then run poorly. That will be a good start. I hope. At least I got my ol' VRod to ride to work while I figure this out ! | ||
| Kurbennett |
I had this problem with my STT when I first got it. Was about a half hour from the dealer. Struggled back, they re-tightened all the grounds and it was good. A thousand miles later it returned, another dealer replaced the ECM. All was good. About 6 months later it returned, I cleaned up and re-tightened the grounds and all was well. | ||
| Jraice |
My grounds are pretty nasty, I think I might actually do that just to be safe. Just rebuilt the fuel pump, got new spark plugs to install as well but I want to attack every angle possible to get this thing running like new again. | ||
| Trojan |
Before you start looking into more complicated matters, check the temperature sensor in the rear cylinder head. This is a known problem and when they go wrong they don't always show up on the scanalyser. The sensor has a single braided wire that you can see disappearing into the square hole in the rear rocker cover and is threaded into the head. The idea is that if the rear cylinder gets too hot it will cut the spark to cool it down. Unfortunately the symptoms of a duff sensor/wire are exactly as you describe  | ||
| Rkutzner |
Trojan, thanks. I was going to start there after checking the grounds because as I noted I don't remember the fan coming on lately (which would tell me either it's telling the computer it's hot before it is or it's not telling it when it is, or neither). So how many grounds am I looking for ? How much wire loom should I buy ? Might as well protect the wiring since I'm going to be checking it all out as a pre-emptive strike. | ||
| Jraice |
Interesting, that is definitely what it feels like (spark being cut out to a cylinder) in my case. Tough to replace? Inexpensive? | ||
| Kurbennett |
I cleaned and tightened the ground connections under the seat including the ground from the battery to frame. I removed the cable(s) at the frame connection, sanded lightly and reattached. I think there are at least 2 frame connections for grounding under the seat. I am overseas right now and cant re-verify. (Message edited by kurbennett on June 01, 2012) | ||
| Trojan |
Tough to replace? Inexpensive? Not too tough to replace, just a b'stard to get to! The sensor is buried deep inside the rear rocker cover and you need a socked with a slot cut in it (to clear the wire)to remove the sensor from the head. I don't think these can be tested or fixed, so you have to just bite the bullet and replace it with a new sensor. Not sure of the current price but over here last time I checked they were around GBP70 (US$110). I'll bet they are much cheaper in the US though. | ||
| Skully |
Matt, The temp sensors can be tested if I remember correctly. The factory manual lists acceptable ranges of resistance based on sensor temp. You can test it without removing it. Keith | ||
| Rkutzner |
I've been super busy but I started checking the grounds and the negative battery was loose enough to wiggle the cable. I cleaned up both battery connections and hope to test soon, though I'm going to look over the other connections first. Will reply back in a week or so.....! | ||
| Iamarchangel |
The other thing about the temp sensor is that its wiring is sitting right on the cylinder. The insulation is heavy but, over time, I don't know. I used a zip tie to suspend it away from the metal. | ||
| Greg_e |
I used a zip tie on mine too, same with the o2 wire. | ||
| Jraice |
"If it can go wrong, it will" I think I'll dig around for these sensor wires and zip tie mine as well! A loose battery connector will wreak havoc, I am sure thats your problem... but a full week before you plan to test it?! Whatttt? | ||
| Rkutzner |
Sorry, the farm is keeping me busy after work and I have a VRod to ride so no hurry ! I finally got around to checking all the wiring under the airbox. First, as I mentioned last week the negative cable was snug but loosed enough that I could wiggle it under the bolt. So I took both off and cleaned them up. Ran it until the fan came on. Turned it off, started it up. So far so good. Then under the airbox. There was some chaffing of the wire that goes down into the center of the valve cover (what IS that ?). But the chaffing didn't look like it went through. The wire off what I think is the Temp Sensor on the back of the head went over the valve cover but really wasn't touching anything. I put wire loom covers over both and zip tied them up just to be safe. So next is to check the wiring around the 77 connector (that was upgraded a long time ago) and then take it to work. Since it's 33 miles I'll have my friend who I ride to work with drive my truck, I'll let him drive one of the ways. If the problem is gone I'm going to assume that battery cable. If not, I guess I'll have to check out the fuel pump wiring..... (Message edited by rkutzner on June 10, 2012) (Message edited by rkutzner on June 10, 2012) | ||
| Iamarchangel |
Hard to figure what you're describing. Into the centre of the valve cover is the heat sensor. Over the rear valve cover to the rear header might be the O2 sensor (I'm guessing) | ||
| Rkutzner |
I think you figured it out just fine! Sounds like you're saying the heat sensor is down in the hole in the middle of the valve cover and the 02 sensor must be on the rear of the cylinder in plain view. I couldn't really see the heat sensor, looks like the wire goes through a rubber grommet or something like that. Anyways, sure hoping it was the battery ground. | ||
| Rkutzner |
After checking out all wiring I finally took her out a couple times, stopping and starting it a few times just to repeat the conditions it happened in the first time. Ran perfect. For now I have to chalk it up to that loose negative battery cable. Just loose enough to slide the connector around under the bolt, but not loose enough to jiggle it. But I guess that was enough. That said, as soon as I run the tank low I'm going to pull the fuel pump out enough to check for that frayed wire problem, but I don't think I'll find anything ! |
