| Author | Message | ||
     Tempest766 |
The 2008 Uly starts and runs fine, but when the engine is hot and I pull up to a stoplight, then after a few seconds (10ish) it starts to idle lower and lower to the point where it is straining to stay running. A few times I've noted the oil pressure light and gave it some throttle to keep it running. It's got 31k miles on it and the voltage regulator was replaced last year. The battery seems fine. Breather reroute at about 10k miles. engine occasionally "pops/burps" back through air intake after deceleration from cruising and then revving the throttle to take off from a complete stop. crappy 93octane 10plus% ethanol gas here. And while I understand that the magical TPS reset will get my shirts whiter, cause me to not need deodorant, and can make me a sexual tyranosaurus, trust me...that's not it. I'm interested in thoughts as to what would cause this, and some technical justification as to why you might believe such-and-such to be the problem. Thanks, Rob | ||
| Natexlh1000 |
Perhaps your intake bypass idle gizmo is sticky from before you rerouted the breather? I took mine out and cleaned it at 50,000 and it looked like dog crap. It's not too hard to do. You just pop off the airbox's "floor" and it's right there. There are other sneaky things that the ECU does when you pull in the clutch so that switch at the lever may be worth looking at too. | ||
| Tempest766 |
Not sure what you mean by "bypass idle gizmo." There is a butterfly valve in the air intake, but other than that the only thing I'm aware of in the intake area is the IAT sensor. Will have to look over the clutch switch then, when I can locate it. | ||
| Phelan |
I would suspect the IAT or TPS sensor. | ||
| Froggy |
On your 2008, the idle is adjusted by an ECM controlled stepper motor called the Idle Air Controller (IAC). That is the gizmo being talked about, and usually is a culprit with idle issues. They get gunked up over time and seem to work better after being cleaned out. That may or may not be the issue here. | ||
| Tempest766 |
I will grab the service manual to see what's involved with getting to and cleaning the IAC as a first step. Thanks. I wish I knew how to easily "test" the IAT sensor. | ||
| Tempest766 |
I pulled the IAC and it didn't look bad at all, just some minor varnishing on the metal ball at end, which I brushed off with a paper towel. I put some dialectric grease on the contacts and reassembled everything, then did the magical TPS reset and went for a 20 miles test ride, 45mph closed loop for the first few miles. After the bike warmed up it still kind of sputtered and groaned at idle when I got over to the area where the gas station and autoparts store is located, but nothing like the other day. I bought some injector cleaner, a fresh tank of 93 octane ethanol enriched crap, and filled it up, then came come. It did NOT sputter or want to die once I got home and left it idling in the driveway while I was opening up the garage. Much cooler day today than when I was out over the weekend though. 75 vs 87 degrees. How much can plugs or plugwires play a part in this problem? The wires are original (30k miles) and the plugs are probably due to be replaced (10kmiles). I'm still a bit nervous about this. Also noting that recently the neutral light doesn't want to come on when the bike it hot. It's touchy, and possibly a bad switch...probably a bear to get to it, huh? | ||
| Natexlh1000 |
Usually plugs being marginal will act up more when on the throttle. | ||
| Tempest766 |
very strange, and kind of scary... After cleaning my IAC and doing a TPS reset my bike seemed to be doing better, not stalling while idling, but to be fair, the heat hasn't been as bad. I took a ride for about 20 miles this afternoon, then shut the bike off for about ten minutes while checking out a river access. On the ride out the thing seemed more "throaty" with a bit more low end torque, but also a bit more vibration than I've previously experienced. When I restarted the bike it idled around 1k rpm, but then started slowly creeping upward so that after about 2 minutes it was idling at 1500rpms and continuing to climb. I jumped on the bike when I put it in gear the idle dropped back to normal so I then rode another 15 miles to get some supper. On the highway at around 70-75 mph I tried to punch it, but the throttle got to a point where adding more throttle actually caused a decrease in power. I honestly couldn't get it to go more than about 80mph. The higher the rpms the more it strained to continue. RPMs topped around 4200 before complaining. I then had some supper and gave the bike time to cool off. When I restarted it it idled fine and when I pulled out I tried to rev it up to high RPMs in second gear. When it hit about 5000rpms something unexpected and dangerous happened. It acted like the engine was seizing and immediately dropped back to around 2000 rpms, with a high pitched clicking as it slowed down (very quickly). I then rode normally in the 2500-3500rpm range on the way home, but the endinge really didn't want to do any more than that anyway. There was absolutely no high end power on my ride home. it's a 2008 XT that had the ECM changed by a dealer when I first bought it with about 1000 miles on it. Bad EMC connectors? bad crank sensor? crap clogging the fuel system? whiskey tango foxtrot, batman? | ||
| Natexlh1000 |
Wow that's creepy. Is there anyone around you with a 2008-2009 that can temporarily swap computers? I wish I lived closer to you. (Also, Massachusetts sucks LOL!) | ||
| Reepicheep |
Up to that point, your symptoms could have been caused by the computer, or by something mechanical. At that point, I don't see how a computer problem could add a high pitched clicking. So it sounds like something is broken. Sorry that isn't very precise or helpful... all I can really say at this point is that I don't think it is computer or IAC related. (<- call me captain obvious) | ||
| Tempest766 |
The loss of power at high rpms seems to lead to shutting off of the cylinders and riding through what is generally high compression in a low gear (think engine braking). I'm hoping that's all it was since it only happened once and didn't seem to leave any other symptoms. I do wish I had some way to try a different ECU temporarily but 2008 and later Uly's are quite rare around here and I cannot really convince myself that a racing ECU is a good deal. | ||
| Reepicheep |
I guess it could have gone into skip spark mode, and that is under control of the ECM, so I could be wrong. |
