| Author | Message | ||
     Arry |
I started a riding/camping trip today, but didn't get far. The bike was running great, but at a steady cruising speed (about 3.5k RPM) the tach needle started erratically swinging up (spiking?). I stopped and checked the wiring coming from the cam position sensor (thinking that is where is gets it's signal.?), and the tach was OK for about 10 miles, then the problem started again. I pulled over for a couple of minutes and decided to head home. It, again, was OK for a while then started acting up again. The ride home was cooler (after sundown) and the tach worked fine most of the way home, so it may be heat related.? I wondering about the cam position sensor, the ECM, The voltage regulator (would voltage spikes maybe cause tach needle spikes?). Anyone had this problem? Any other ideas? | ||
| Britchri10 |
Check your stator.... | ||
| Buewulf |
Mine was doing that. I had three broken wires in that mass of wires that runs between the frame and left fork leg. One of those wires apparently fixed the issue (knock on wood), because the tach hasn't behaved erratically over the last 200 miles since the fix. | ||
| Etennuly |
Likely one of two things, well, where to start looking.....The wire bundle as mentioned and the ground wires on the steering neck behind the headlights. Any of these things can be broken and look fine. You have to remove and inspect them closely. | ||
| Reepicheep |
If it was the CPS, it would have been cutting out and backfiring. The wires are hard to spot as broken visually (because they break the internal conductor, not the soft insulation). But when you run them through your fingers flexing them slightly, it's as plain as the nose on your face. They are easy to find. | ||
| Arry |
Buewulf. My tach needle is spiking upward only. When you had a problem, was it doing the same? It seems like a broken wire would cause the tach to drop off or dip (instead of spiking up). I guess this is a good place to start looking. I'll also look at the grounds at the steering head (I did a mod there quite a while back to make the grounds more flexible). Thanks for the responses. Any other ideas would be welcome. | ||
| Froggy |
Given that only the tach is being erratic, and the bike is running fine otherwise, I suspect it is the wire the tach uses for its signal, likely damaged in the steering neck like Buewulf had. I agree that if it was broken it should drop completely out, makes me think you might have multiple damaged wires and it is getting input from something else. | ||
| Claybobber |
That happened to me too, turned out i had pinched the pickup wire when tightening the the pulley cover plate. The wire was broke, but the insulation was not. Its worth a look. | ||
| Buewulf |
Arry, I can't recall for sure, but I believe it did initially spike upward when the symptom first manifested. Not long after, it started dancing all over the place. Still mostly upward from the true rpm, though. | ||
| Buewulf |
Come to think of it, I had also had that problem once before, and there was insulation on two of the wires going into one of the ECM connectors that had rubbed off to the bare wire in one spot. Taped them up, and it worked fine. Pressure on the ECM connectors can also cause this. Even if you relocated your ECM, you may want to make sure that nothing is pressing on the connectors or even the wire bundles going to the connectors. | ||
| Arry |
I checked the steering head gnds-OK. Removed the plastic guard and unwrapped the wiring loom where it comes around the steering head. I checked these wires individually, but didn't find a suspect. The pink wire from the ECM is the signal to the tach, I believe. I checked at the ECM to make sure the seat isn't contacting the ECM/connector (I have a support on both sides of the ECM to keep the seat from sagging) all looks good (no seat contact). Froggy, the idea of multiple damaged wires seems possible, but I haven't found anything questionable in the wiring I have exposed. Thanks for all the ideas. | ||
| Etennuly |
You are working on an '07 Uly? Right? When inspecting that wire bundle at the steering neck did you find two three into one wire splicers? If so they will be cold crimp wax filled splicers inside heat shrink. Mine broke in such a way that I had to cut the insulation clear off from it to find the break. I used a single splice to replace the triple splicers and moved the triple splices up into the fly screen area to reduce the number of wires that have to flex in that bundle. | ||
| Ryat79 |
Check your Regulator, it fixed my erratic dial readings. | ||
| Arry |
I did a lot of checks on wiring and connectors, also drilled out the rivets so I could look at the cam position sensor yesterday. Every time I took it for a test ride it's OK for 5-10 miles, then starts spiking. Ryat, mine is having problems with the tach only. If it were the VR I think I would see problem with the speedo also (?) and flickering lights (?), but I'm not sure. Etennuly, I tugged on the wires at the triple splices and they seemed OK, but maybe I'll open them up again and cut the heat shrink off | ||
| Reepicheep |
Got access to an oscilloscope? That makes it easy to check the CPS. | ||
| Arry |
Reepicheep- I don't have access to an osc. Unfortunately I don't even have Tunerpro or Spy, so I'm checking the things I can without getting involved with a shop. Etennuly- I cut open the triple splices and at least found the intermittent problem with my right turn signal (brown wires), the reds might effect the tach, but they seemed OK. | ||
| Etennuly |
Next remove the voltage regulator. Check the back of it for cracks. | ||
| Arry |
I took a look at the back of the VR, it looks OK. Also I temporarily hooked up a multimeter, and went for a ride. I didn't see any voltage spikes, and it seemed to settle in at 14.21-14.25V, then when the fan kicked in it dropped to about 14.04-14.06V. These readings seem about right, but I haven't found the spec.s in the service manual. On this 70 mile test ride it started out with the same tach problems, then for the last 40-45 miles the tach was working fine..?? | ||
| Natexlh1000 |
I wonder if the problem is the tach itself? It would be the first time I have ever heard of this but it is made by humans and therefore able to break. | ||
| Reepicheep |
Those volt readings are good, but with a DVM you won't see transients (which could be substantial). | ||
| Arry |
Maybe it is the tach itself, it has started to dip or drop off (even to zero) along with the spiking that it started off with. Good point about the DVM not catching transients. Sometimes when the tach is spiking it holds at elevated readings long enough that I think the DVM should show something -- if it is a voltage problem (Message edited by arry on September 11, 2014) | ||
| Etennuly |
Those red wires are the power sources for everything up in the flyscreen area. It still sounds like a broken wire or bad ground to me. This intermittent problem type stuff can be a bear to find sometimes. How do the wires at the ECM plugs look, are they a twisted group spinning into the plug? Mine had an issue with a couple of wires that laid into each other too long wearing through into each other. Try unplugging the ECM plugs, un-twist them one revolution while inspecting them closely, and plug them in with this new position. | ||
| Arry |
I went ahead with my riding/camping trip (10 days/~1800mi), in spite of the tach problem. The Uly ran great (mostly) even though the tach continued its intermittent jumping around. Also, another intermittent problem I've had (for over a year), where the engine cuts off briefly then the check engine light comes on for just a couple of seconds, seems to be happening more frequently. The tach problem seems to occur after the motor has warmed up some (5-20mi), and seems to go away after it's heated up thoroughly (50-100mi), and the engine cutting out seems to happen, most often, while the tach is acting up. So, I'm still stumped, but thinking it's an ECM issue. | ||
| Buewulf |
It definitely sounds like the ECM, Arry. | ||
| 05mxdiesel |
Arry, my bike has been doing the same thing as yours for a couple of months. Although mine has zero issues with shutting off. I ride 28 miles to work and at about mile 15 the tach starts jumping. After about mile 25 the tach settles down and returns to normal. It almost seems like it is relevant to the throttle opening. Open the throttle it jumps, steady throttle doesn't jump. I have not had a chance to look at it yet as everything else is great. | ||
| Arry |
mxdiesel, sounds like the same problem, but I haven't messed with it lately. Mine also seemed related to throttle opening, as in only at cruising RPM (3500-4000), but as it's gotten worse does it at lower RPM's also. I suspect the ECM, but need to take another look at the wiring harness around the steering head and unwrap a longer section, before deciding to order an expensive ECM. It does seem weird that they're OK when we start off, then go wacky for a while, then seem to settle down after several miles...??? | ||
| Etennuly |
It does seem weird that they're OK when we start off, then go wacky for a while, then seem to settle down after several miles...?? That is a good description of an intermittent wiring problem. The two triple splices in the wire bundle are wax filled cold crimp splicers wrapped in heat shrink. Mine and most that I have seen have the ridged splicer break. you can't see the break because of the heat shrink, and the wax fill makes it feel like it is not broken. I cut the heat shrink off from mine to have one of the red wires simply fall off from the splicer. All of that heat shrink and wax hold it nearly perfectly in place to cause contact most of the time. It heats up, or the bars move the right way and contact will be lost momentarily. | ||
| Buewulf |
"you can't see the break because of the heat shrink " If you haven't yet, move those splices behind the flyscreen whether you think they are broken or not. Because they will break eventually. May get lucky and find it fixes your problem. At the very least you will fix a future problem. When my ECM went bad, it caused running issues in addition to tach anomalies. Sputtering, backfiring, check engine lights which all grew progressively worse as time went on until the bike was unrideable. In the very beginning, though, it was just the tach and an occasional hiccup, and only when the engine was hot. |
