| Author | Message | ||
     Turbo6bar |
I really could use some advice. I bought my XT 3 months ago. I've only ridden it half a dozen times. Yesterday, it would crank over and fire, but would never hold and idle. It would always stall. Today, I removed the airbox and pulled the Idle Air Controller to ensure it was clean. There was minimum amount of residue (oil/carbon) mixture where the controller "pin" seats in the throttle body. I cleaned it and the throttle plate so it was all very clean. Well, the problem persists. I checked the battery connection and two grounds adjacent to the fusebox. All connections were tight. I connected a battery charger to the bike and it did turn over better and started better, but it would never idle. I can hold the throttle at 2000-4000 rpm and the bike will run, but it seems to be missing, coughing, and backfiring every so lightly. But, when the throttle is dropped, it will promptly stall. BTW, when running at higher rpms, I held it for at least a minute or two, presuming that it would get warm and need less input from the idle air control. Despite that, it would still promptly stall when the throttle was closed. Also, the handful of previous times I have ridden the bike, it started slowly, but always picked up a lumpy, but decent idle. The bike ran fine, but take that with a grain of salt as Buells are so new to me. I know that troubleshooting this to a SINGLE issue is tough for you all, so I would appreciate any places to start. I considered the prospect of bad fuel, but would that cause the engine to die so quickly once the throttle is closed? I ran a tank of fuel to 93miles on the trip odo, and I filled it with some fresh fuel from a fuel can (perhaps 1.5 gallons). The tank is nearly full, now. Thanks much in advance. I have been lurking here for the last two months soaking up the valuable information. I really appreciate the time you guys spend here. Many thanks, Jurgen in Memphis, TN | ||
| Hughlysses |
It's possible the IAC is just defective. Simplest thing might be to just replace it. | ||
| Turbo6bar |
My brother and I waited for the sun to go down some before troubleshooting further. We checked the front spark plug and wires. Everything looked fine. Removed the fuel pump fuse and turned on the ignition. I placed the IAC in my hand with wires attached. When engine was switched to run, the IAC pushed the pin out. It seemed to be doing something alright. Fired up the engine, and I began spraying starting fluid onto the butterfly. Well, the engine would finally idle. A squirt every couple seconds would produce an idle that would go up and down between 1500 and 1000. I am now thinking this is fuel related. I need to do some searching on draining the fuel tank and pulling the fuel pump. I have read the fuel pump, connections, and filter can introduce problems. Jurgen | ||
| Griffmeister |
"I can hold the throttle at 2000-4000 rpm and the bike will run, but it seems to be missing, coughing, and backfiring every so lightly." That right there sounds like a fouled spark plug. The starting fluid may just be making it easier to fire. The 08's and up have a plug cleaning mode you can try, but if the plug is bad enough that's not going to help. The cleaning mode is also the same way to check the exhaust actuator. Key off, hold WOT, key on, run switch on. Do not start the engine. Turn everything off and repeat a couple of times. What happens is every time you turn the run switch on at WOT, the exhaust actuator cycles once and the spark plugs fire a few times. This will clean a mildly fouled plug but if it's really bad, you have to just change the plug. | ||
| Firemanjim |
Check for intake seals leaking. And iac has an adjustment to set minimum idle,should be open enough that 4 thou feeler gauge fits in tb when closed. | ||
| Hport |
My 2 cents, #1...Keep it simple, I have an 08XT and had something very similar to what you are going through shortly after I purchased it 2/14 Went through the basics, found fouled plugs ( PO rode it a couple hundred miles in 3 years…) none of the mods were done, cables not adjusted and so on. But nothing really pointing to poor idle, stalling and random misfire. The main problem and probably the cause of most of what ailed it was a cracked ECM ( read about here on BW) Replaced the ECM, went through and sorted out and adjusted per service manual, did the grounding and breather mods, installed K&N filter, new plugs, removed and cleaned IAC and the bike been running great for 3K miles I'm sure you will get answers and all the help you need to sort out your problem(s) here on BW. John | ||
| Turbo6bar |
Well, it is update time. Still no luck. I bought a set of NGK plugs (not the preferred Iridiums, but ones that crossed over to the stock 10r12a HD plugs). We installed the plugs and new Magnecore plug wires. Put it all together and the engine is the same. It will not start. It will sputter and eventually start if I crack the throttle while cranking. It will start if I hit it with starting fluid. It will hold idle if I keep squirting it with starting fluid. After starting and holding constant open throttle, we notice the rpms will fluctuate up and down slightly. You can hear the engine note change slightly. During testing yesterday, we sprayed the intake seals with carb cleaner and detected no change in engine note. Firemanjim, how do I get a feeler gauge under the IAC when it is bolted in place? Hport, I recently purchased a used, known working EBR Race ECM for my 08 bike with stock exhaust. I installed the race ECU, reset the TPS, and the starting is equally poor. I don't believe two ECUs would show the same condition. My brother removed the fuel line from the fuel rail and upon flipping engine switch to run, the fuel pump would pump about 1 cup of fuel into a jar, before the pump timed out. I presume the pump runs for a preset time, and there is no fuel pressure cutoff. I should have purchased a service manual some time ago. I didn't think I would be diving into my baby so soon, though. That's what I get for thinking! Next round is checking wiring. I want to be sure the injectors wiring is good. I want to check wiring near steering as well as wiring near ECU. Fun times! | ||
| Mark_weiss |
Why not try resetting the throttle position sensor. If the TPS calibration is off you'll experience all of the symptoms that you mention. Reset process is built in and free. http://badweatherbikers.com/buell/messages/142838/ 657968.html?1321200051 | ||
| Rayycc1 |
Man I swear i went thru this same thing last week....and honestly....My bike is now running better than ever and i have no idea why. When i had the problem was just after a cold tps reset...the bike refused to start and would backfire if i opened the throttle.... when i did get it running by slowly turning the idle screw until it would idle ( had to turn it way to far in for normal idle)....the idle would vary from 2000-4000 I finally got her running good after by replacing my tps sensor ... I believe my tps sensor was going bad ....and even then it ran rough....and i mean extremely rough for the first ten miles...then it just all of the sudden smoothed out and started running great. It could have been dirt at one or both injectors for all i know...i'm still not truly convinced it was my tps....I know what you're going thru though....its a frustrating problem and i really hope you get it figured out. for what its worth....your bike is doing EXACTLY what mine was | ||
| Tootal |
If you can get it to run then ride it for 20 minutes and then to a hot tps reset. Then ride it over 3000 rpm for a while at a steady speed so it can learn from a proper tps position. | ||
| Mark_weiss |
'08 and later do not have idle speed adjuster screws. Idle speed is set by the ECU (using a motor controlled port). | ||
| Turbo6bar |
It is update time, again. We reset the TPS at least a dozen times over the past two days, but the bike would never start without holding the throttle open. I searched here about testing the TPS, and came upon several threads telling guys to reset the TPS, start the bike and ride it a long distance to reset the AFV and begin the calibration process. I geared up and started the bike. I resolved to ride the bike no matter what happened. By mile 4, the bike was getting better. After 8 or so miles on the interstate, trying to hold constant throttle, it would finally idle and not stall. Wooohooo! Upon returning from the trip, I restarted and the bike and it held an uneven idle, but didn't stall. Success! I plan to run the bike several more times to get the ECU tuned well. Then, I am going to install the Race ECM to see if it is really worth the hoopla. ECM relocation is an absolute must. Thanks to all that responded and read. I have no proof, but believe the TPS needed to be reset. In all instances previous to the recent trouble, I always had to crack the throttle to start the bike. | ||
| Turbo6bar |
BTW, I did not think my 08 needed a TPS reset when the engine was hot, so naturally I assumed the ECM did not need runtime after a reset. That's what I get for assuming. The way the engine was running, I never thought it would be remotely possible to ride it. Darn Buell had me fooled.  | ||
| Rayycc1 |
strange...like i said. same symptoms as mine....and apparently the same fix. Strange. | ||
| Tootal |
Woo Hoo!  Glad to hear it's running better! The injection on these bikes is different than any other bike. It takes so long to learn it seems antiquated but in the end it does work, just a little weird!  |
