| Author | Message | ||
     Dnchevyman |
I have noticed, on my x1, only 2 times since putting the race ecm on, a miss. Its always going down the interstate, cruising at a constant speed, all of a sudden, its like 1 cylinder didnt fire, you just barely notice it. and then its back to normal. happened maybe 2 times in 400 miles. any ideas? | ||
| Iamike |
My S3 did that too, much less with the race ecm though. It is kind of disconcerting though isn't it? My ST1300 kind of bogs down just a little when running at steady throttle when I try to accelerate a little. Probably just something with the fuel control. | ||
| Natexlh1000 |
Mine has done it too ever since it was new. I went out of my way to beat on it the first year so that it would finish breaking under warranty. Pretty much didn't break but all sorts of other things broke! It seems to be made worse by any bad connection of the Oxygen sensor or grounding of the exhaust. It never goes away all together. It's mostly random. It will do it with the stock muffler too. If you cruise at 75, it doesn't do it as often. It doesn't do it when I'm flogging it on curvy roads, only on boring highway runs with the throttle in one place for long amounts of time. It really does seem as though the bike gets BORED of the highway and protests. I've only ever had the race ECU so i don't know what the stocker would do. | ||
| Jramsey |
My 2000 X1 has done that since new, I thought it was a typical Harley trait. | ||
| Jos51700 |
Jramsey is correct. It's just a Harley trait. It's a combination of harmonics through the common intake and the odd occasion when one cylinder sucks most of the air and fuel for both. The remedy? Twin intakes. HD tried it with the (Thank God) long-gone Magnetti-Marelli FI of the late '90's. If you think DDFI is bad... The M+M bikes did idle better and run better smoother (and people bitched about it), and so along came Delphi FI for HD (Great stuff). Most stock Harley's don't hiccup running down the road like that, but high lift cams and racy, open exhaust make it worse (i.e. Buell). Listen, I mean really listen to your bike idle sometime. Part of that lope is 45 degree firing order, and part of it the occasional miss. It's very noticable with an open-baffle 2:1 header. | ||
| Natexlh1000 |
Mine doesn't miss any at idle once warmed up. My Ironhead? hell yeah. My friend's M2 doesn't ever miss on the highway. It does do the traditional harley missfire at idle though. My other friend's XB12 has a single throttle body and it runs flawlessly all the time. I don't think it's the single throttle body architecture that's doing it. I'm pretty sure it like a code bug in the brain. I think we should compare the datecodes of our brains. Perhaps we all have an earlier revision? We all have race ECUs, right? Anyone here with a stocker that backfires on the highway? | ||
| Ackme |
I have an '02 M2L which occasionally misses on the highway, and also has an occasional backfire. It is as stock as they come. (Message edited by Ackme on June 06, 2008) | ||
| Jos51700 |
"I have an '02 M2L which occasionally misses on the highway, and also has an occasional backfire. It is as stock as they come. " And has no ECU to speak of..... But, blame the computer anyway. Right? | ||
| Psykick_machanik |
Mine only misses when its not fully warmed up. here in Alaska it takes between 5-8 min. to properly warm up. If I jump on to soon it will miss a few times. | ||
| Mbsween |
My X1 does that a lot. It still scares the bejesus out of me when it happens on a long boring superslab ride. It happens less since I changed out the intake seals, but its still there. I also get the near stall when blipping on downshifts, but only when going from 2nd to first Bike is a 2001 X1 with a race ecm and forcewinder, it has approx 40k on it. | ||
| Dnchevyman |
I think its safe to say its a buell thing, and totally normal and to be expected. | ||
| Mcgiver |
my s3 was doing this and I noticed the tach would also take a big dip and come back to normal. I found (eventually) a broken wire in the harness from the cam position sensor. Haven't had a miss cruising since. Brian | ||
| Oldog |
Mine does that too, with an occasional back fire if I am tickling the throttle. One question for force winder bikes where have you located your intake air temp sensors. I think that in slow traffic that they get hot air( depending on location ) and that fowls up the computer miss on highway, perhaps a little water in the gas passing through? | ||
| Mbsween |
I have the XR2 with the AIT in the filter itself. I highly doubt the water thing, Mine does this at least a couple times a week. Doesn't change if its dry or wet. I get Gas all over the place, so unless all the stations have water in their tanks, then again where I live that could be snow.... (Message edited by mbsween on June 08, 2008) | ||
| Oldog |
Matt take a look at the gas cap where the latch handle is water can get in mebe. get Gas all over the place, so unless all the stations have water in their tanks, more common than you think. I am going to have to replace the filter (mech damage) does the XR2 filter have knock out bungs for the sensor / vent or would I have to plug the vent line hole. one other thought on the ocasional miss possible vibes & BAS (Message edited by oldog on June 08, 2008) (Message edited by oldog on June 08, 2008) | ||
| Natexlh1000 |
If the BAS gets tripped, it kills the engine until you turn off the ignition and restart it. I really doubt that it's water in the gas since mine does it rain or shine on long trips with multiple gas stops. The intake air temp theory might make sense. When the monkeys at Boston H-D gutted the airbox, they tied the sensor to the top of the airbox. It would run like crap in heavy traffic on hot days. I have replaced it with a forcewinder and that made the bike run much better. the sensor is in the path of the intake air inside the filter element. Also, not having sand in the intake seems to help a bit. Everything I do to make the engine run a bit better makes it backfire less often on the highway.... but never actually cures it  | ||
| Mmmi_grad |
My X1 is approaching 10k miles and is still stock but thats about to change. however I am hearing some more lifter noise that I have to track down and make sure mounts are up to snuff. I would be pissed off If it was back firing. With the Race ecm I could understand slamming the throttle shut and getting a lean backfire. Backfires are not good news. You will not get a backfire being too rich, just lean. Id like to hear from someone that has a low mileage bike with a race ecm that does not backfire......... |
