| Author | Message | ||
     Juniorkirk |
Ok, i was just riding yesterday until i took off from a light and got into it and missed 2nd and put it in neutral and pegged it. Since then it has been acting like crap. Symptoms: starts missing at about 2500 rpm and gets worse til about 3200 then gets a little better after that. If i WOT it wont give me any problems, and it idles perfect without missing a beat. I changed the plugs today and checked all the wiring and nothing is wrong. Could it be in the ECM or a sensor? Any help with this would be great, my bike is my ONLY means of transportation and i have to be at work on Wednesday. | ||
| Ironhead1977 |
Before any more damage is done, pull the valve covers and inspect the springs and keepers. | ||
| Pogue_mahone |
if a valve let go it would have knock/dead cylinder all the time. | ||
| Juniorkirk |
It only happens if i take off normally and at about 2500rpm it will start missing and get progressively worse until about 3200rpm and after that it gets better until about 4000rpm when it's almost nonexistent. and if i take off really hard it goes through it without any problems. Could it have to do with the TPS or sensor knocked loose that is giving bad data to the ECM to make it miss in that RPM range? | ||
| Froggy |
It sounds like your AFV is out of wack and running the bike excessively lean. Check and reset the AFV with ECMspy. If it runs great for a little bit then comes back, I suspect a bad O2 sensor. | ||
| Juniorkirk |
I dont have a ECM cable, and i'm too scared to mess with it cause a small computer problem can end up with a BIG mechanical problem. I did think of the AFV and TPS, but the O2 sensor didn't cross my mind. Does it just go bad all the sudden, and how can i confirm if it has gone bad? My engine light doesn't come on (only when you turn the key on, but that's normal). | ||
| Iamarchangel |
Wouldn't a hard half hour run get the ECM to relearn everything? | ||
| Juniorkirk |
That would be nice if it did, but i really don't think it could make it. at cruising speeds, it misses a lot and jerks the bike a little too much for my comfort. the only way i might be able to do it is if i keep it at about 6000rpm the whole time, then it wouldn't miss as much | ||
| Froggy |
No, because it only learns and adjusts the AFV under certain conditions. Riding the bike hard, like holding 6000rpm would not do it. Juniorkirk, you already have a small computer problem. ECMspy is no different than a hammer, you can use it help install your muffler, or you can use it to smash your finger. It all comes down to how you use it.  | ||
| Ourdee |
Did you get your gas at a different station? Is the tank down to a 1/3 or less? | ||
| Juniorkirk |
Gas is from the same stations that i usually get it at. And i have about 105 miles on this tank. I usually get about 150 miles before the gas light comes on. | ||
| Buell_41 |
does it miss under 2500rpm with it in gear and moving? | ||
| Juniorkirk |
no, under 2500rpm, there is no problems, in gear or not. | ||
| Buell_41 |
ok so 2500rpm to like 4500rpm (I think) is the range in which the bike learns (must be steady state riding). Disconnecting the O2 stops this and the bike is forced to run at the last acquired AFV across all conditions. If you had the USB cable this would be really easy and take about 2 minutes. If it were me, I'd force in an AFV of 100, disconnect the O2 sensor, ride it and see if that fixed it. This would indicate a bad O2 as Froggy eluded to. You could try disconnecting the O2 and see what if that changes anything. It doesn't sound like a mechanical problem but you really need ECMspy and the cable to be sure. ECMspy can be used as a viewer only were it reads the info from the ECU but doesn't change anything. No risk of harming anything when used like that. | ||
| Froggy |
Yep its only goofing in in closed loop. You need ECMspy at this point to narrow it down, or you will go nuts replacing sensors and junk till you get it. Hell it might be nothing at all and the AFV reset could cure it. | ||
| Buell_41 |
right so if it is an AFV problem, it will not go away with the O2 disconnected because it will still be using that goofed up AFV. Need ECMspy to reset it. | ||
| Brumbear |
reset is the way to go especially if the bike aint throwing a code | ||
| Juniorkirk |
does anyone in the san diego/oceanside area have a cable up for use and maybe some expertise? | ||
| Froggy |
You are withing pissing distance of American Sport Bike, I recommend you drop by and get a cable from Al. We can help you from there. | ||
| Juniorkirk |
It's been a few weeks since i was down there to see him. When i get a free chance i'll head down there, but will probably be awhile until i get some free time. |
