random miss on highway

[drebinpk]

Hi I recently purchased a 2009 xb12r that has a hawk exhaust, airbox delete, and race ecu and I have noticed when im cruising down the higbway at a steady speed it has a random missfire that seams to happen once every few miles but other than this the bike runs strong and doesnt miss a beat I was just wondering if someone could point me in the right direction on what could be causing this it is becoming very annoying anr I dont want any serious damage to happe. Cause of it

Thanks

 

[buellbradski]

Fuel pump?fuel line? Hard to say realy it could be a ground wire too.

 

[sicsteeth]

i was exspecting a photo of a chick on a bike...damn you's titles!!

 

[Infernorodz]

How old is the fuel? Did it sit long? Fuel filter, pump possible.

 

[captain13ron]

I had that happen to me, also my instrument gauges would drop to "0" then back to normal in a 1/10 of a second. it was a bad ground on the battery on my bike, all you can do is check all connections, especially your coil and plug wires, replace the spark plugs just for good measure. and of course what the others mentioned in the above post.

good luck!

P.S. my car had this happen a well, once every 50 miles, VERY frustraiting! the dealership was stumped, then they finally found a bad mass air flow sensor. it would change the fuel/air mixture and make the car miss.

 

[Dave A]

plug wires

 

[drebinpk]

ok so heres where i am right now im nearly positive it isnt fuel pump or fuel filter since i replaced both 2weeks ago when i was lokking at wiring and connections i noticed that a wire going down to the center on the rear cylinder head has a bare spot im assuming this is the injector wire? is it possible that this is causing it and do i need a whole new wire or can i just repair the bare spot and be ok?

 

[user_deleted]

on fuel injected bikes if you feel a lag or laziness or what i call the bike "falling on its face" during throttle roll-on, it's fuel related. the miss you describe is ignition related. you did not list as part of your original post any work you did on it or its mileage but it is definitely ignition related. do the easy things in this order: either go to this site's search tab and search 2009 tps reset and follow instructions or google it. very easy to do on your bike. then repair the wire you mentioned above. it sounds from your description it's the wire to rear cylinder heat sensor but don't know without seeing it....but repair it. lastly, check your spark plugs for age and condition as well as the spark plug leads and connections to the coil. it is under air box base plate on left side of top of engine by frame. this is assuming your battery terminal connections are tight and corrosion free.

 

[drebinpk]

ok so heres what i found the possitive battery cable was a little loose tighened that all other wiring looked good so i decided to pull the plugs for the heck of it and found that the front cyl had a DCPR9EIX and the back DCPR8EIX no idea why the previous owner would have used differnt temp plugs but will be switching the 8 out for another 9 asap and let you know if that does it. have a set of oem plugs i might give a try till im able to get another 9 in no one seams to sell them locally

 

[Theycallmecrash]

Your miss if not corrcted by plugs, what RPM? 3000, light load?

 

[drebinpk]

ya its right around 3000-3500 and only when steady cruising on highway only did once today on my 30mile highway ride havent changed plugs yet though so we shall see and other than that i runs great

 

[buellbradski]

I had dcpr8es's in my bike a few years ago any it ran awful. I've heard some on here like 8's better some say 9's? I had a cough at idle , awfull decel pop and a miss when accelerating . I'd guess this is your problem.

 

[Theycallmecrash]

The scientific backing behind this is slightly beyond me, but i had a miss same conditions got worse in rain some reason. Read a while back somewhere about the poor grounds these bikes have, and the fix was a 10ga wire from neg battery post to the coil mounting bolt.... Miss completely gone.... As a test i disconnected the wire ran it... Miss was back.... Reconnected.... Gone. Something to consider

 

[drebinpk]

thanks for the tips everyone gonna buy a new plug tomorrow and ill go ahead and the the added groud strap for good measures
will keep you guys posted gonna be cold tomorrow so might be wed before i take it out for a spin

 

[user_deleted]

sir: the 8 in the rear cylinder is one range HOTTER than the 9 in the front cylinder. generally speaking on these buells, the 8 is a bit too hot. i would replace it with a 9. what crash mentioned above is a worthwhile add-on if you are down in the coil area doing any work. a proper ground to any of the coil bolts have helped a few owners with same condition as yours. in all honesty i have 3 buells and each of them will "hiccup" perhaps 1X during an afternoon ride.

 

[SlyFox]

If it feels like it's switched off and back on within a second, it might be the ECM (or ECU?). H-D in Little Rock took 6 wks. and 6 trys to figure that one out. Mine would do that multiple times in 1 mi. or skip 20 mis. before doing it again. Even had an H-D rep visit LR from Dallas after the 5th try and it was his suggestion to change the ECM (or ECU?).

 

[drebinpk]

Well replaced the plug today and havent had it on the highway yet but it does seam to be running all around smoother!

 

[deviantspeed]

Good to know drebinpk! I had a slight stumble on the freeway the other day, going to clean things up/ground.

If you remove the "tank", are the plugs easy to get to?

Damn, I really need to start a new thread.... going....

 

[drebinpk]

do a search on google with the proper tools changing the plugs isnt too hard just allot to explain
side note why is the search function on this site so inaccurate with results?