| Author | Message | ||
     Sanjuro |
Hi folks, I’m having an issue with the idle not going back to where I set it since my last TPS reset. I’ll try another reset (yes, the throttle position was set to zero and engine warmed up prior to doing it) but I wanted to ask the board first. The issue: It’s intermittent. I’ve set the idle to 1050-1125 range when warmed up. Upon start up, it idles just fine. But after a few minutes of riding, when I stop, the idle doesn’t go all the way down but seems to hover around the 2K range intermittently. The temporary fix seems to be to put load on the engine; as in, engage the gear with break applied briefly. Any thoughts would be appreciated. N. | ||
| Andrejs2112 |
Set the idle to 950 or whatever you like. 950 is best if you ask around.Ride it for about 5 miles at a steady RPM at about 55-60 MPH. Try not to vary the RPM. Steady is best. That should set the AFV and should remedy the "hanging rpm" issue. Search this site, it's been talked about. Hope this helps. (Message edited by andrejs2112 on February 15, 2009) | ||
| Sanjuro |
Thanks a bunch. I've seen it talked about but couldn't remember the details. Cheers. | ||
| Etennuly |
Yes, 1050 is the spec, however many of us found that it is too close to the 'upper edge'. Bring it back to 950 to 1000 and give a try as per the above method. | ||
| Rotorhead |
Check your cables where they enter the throttle housing. Some times the back out even under the rubber boots. | ||
| Ulynut |
+1 on checking the cables. Could be a bad cable, or like Rotorhead states, could be loose. Do you lube your cables at service intervals? | ||
| Sanjuro |
Good points guys, appreciate it. It's been a while since I've last lubed the cable (2 or 3 oil changes a go); I did try moving the throttle forward during high idle, didn't seem to make a difference. Good thing to check though. Added to my to do list. Mental note: +1 beer of "garage time" justified. | ||
| Jlnance |
Sanjuro - It's probably the idle, as others have stated. The Uly does seem to eat throttle cables though. With the bike off  If you open the throttle all the way, and then let go, does it snap itself shut? If not, you may need new cables. | ||
| Snowscum |
Intake seals...... | ||
| Sanjuro |
Over two beers in the garage (Ever wonder why beer seems to taste better in the garage?), I've lubed and adjusted the throttle cables (they weren't loose but noticed that the rubber boot on the return cable had slid down off the adjuster). The throttle slack is just right and springs right back smoothly. I can't seem to set the idle below 1100 RPM range =ing below the throttle position of 6.5 w/o difficulty in starting it back up once cooled down. Unless there's another way to set the idle lower via the awkward to reach adjustment screw (near the air-scoop), the TPS setting of 6.5 resulting the idle of around 1100 seems to be the lowest that I can go. I'll report back after a ride report. | ||
| Edgydrifter |
I'm with Snowscum. Check for a leak somewhere in the intake--a crack in the throttle body, a tear in one of the gaskets, something along those lines. As the motor warms up a tiny gap can open up enough to cause your idle to surge and run high. Carefully spraying carb cleaner or propane around the area can help you pinpoint a leak if one exists. Listen for the idle to even out and increase as the gas is sucked in through the gap. Wear hand and eye protection and keep a fire extinguisher nearby. This procedure is common and usually safe... usually being the key word. | ||
| Etennuly |
Yep, tend to agree about a vacuum leak. I found a plug cap missing on one. It is on the right side of the TB sticking straight up. (Message edited by etennuly on February 17, 2009) | ||
| Buelldyno_guy |
We saw this a couple of years back on the over the counter Buell Race ECM's. I tried several times to find a direct mechanical cause, but and ended up believing it was part of the heat management in the ECM. It does act different between the stock and race units. There are a few things that can skew the idle RPM. Once an XB is in closed loop the and the engine hot any amount of an intake leak will raise the idle speed. On the new bikes with DDFI-3 it is the IAC that controls this function and not the TPS. But back to the issue at hand I have found that after checking all of the above listed mechanical issues, if I try and set the idle speed closer to the low side, say somewhere between 950-990 it helped. Part of the heat management skews idle speed when hot and in doing that bikes would run around fine, but at the end of a good hard set of twisties where you just hammered it then stopped at a stop sign, the idle would hang a little, but then drop back down as you described. We also saw the same thing on a "Track Only" bike. However if the set speed was just a little lower the ECM may still bump it, but just not quite as high. Hope this helps. Terry - JT&S Performance | ||
| Andrejs2112 |
When the idle bottomed out, did you turn it up a bit and try to turn it down again? My Uly needs that kind of tweaking back and forth to get it down sometimes. | ||
| Mnrider |
+1 on the beers taste better in the garage. | ||
| Sanjuro |
I've taken a short ride; the idle still seems to hang. Wow, thanks for all the advice. It's about time to inspect/clean the K&N air filter anyway... check the seals, 2 more beers. I'll follow up. | ||
| Sanjuro |
I forgot to respond to your question Andrejs, but yes, I've tweaked with it to make sure it wasn't sticking... good point though. | ||
| Sanjuro |
Problem solved. The combination of applying throttle cable lube with another TPS reset seems to have cured the problem. One difference this time prior to the TPS reset was that the throttle didn't need to be nudged to show zero prior to the reset. (Message edited by sanjuro on February 23, 2009) |
