Help me diagnos a problem

Don Hardcastle

Busa Ridin' Sailor (ret)
Donating Member
Registered
Went for a ride today first time in a couple of weeks that we have been able to ride.

First thing I did today is turn on the accelerator pump feature with the following settings 90% sensitivity, 15% fuel, and 20 revolutions. I have never had it turned on before.

Shibumi and I took off no probs. 20 miles into the ride, we got the opportunity to pass a line of cars; we were running between 45-55 mph. I downshifted to 2nd, leaned out, and hammered it. Somewhere between 7000 and 9000 rpms in 2nd gear, the bike stuttered. Felt almost like the blip when you hit the rev limiter, did it just one time, I up shifted to 3rd, bike was still pulling like a train, grabbed 4th and rolled out of the throttle. It did it again during our ride, only in 2nd gear and it seems like I can reproduce the blip at will again only in 2nd gear. The first thing I thought was the clutch, so I slowed down to a crawl in 1st gear, hammered it, nose came up shifted into second nose set down softly, no blip in 1st, hit the rpm range up there in 2nd, blip. I think it is probably not the clutch since it didn't do it in 1st. My next thought was I have read of bikes that have 2nd gear a little more worn than 1st gear and thought may the tranny was slipping somehow. I made the last turn for home, dropped to 1st one more time, hammered it, accidentally hit the rev limiter and the FI light came on. I shifted into 2nd, 3rd, then 4th, to get the rpms down. The FI light stayed on but the bike seemed to be running fine. Got home shut the bike off, started it right back up and the FI light is off. This FI light thing happened one other time that was at the Meet N Greet. I shut the bike off, started it back up, no light, no probs.

My bike has 12,251 miles on her. I ride aggressively but nowhere near, what some of you guys do. The bike has never been to a track and the front wheel has been off the ground maybe 8 times in 10656 miles that I have owned the bike so the worn 2nd gear theory is a little weak too.

I am wondering if there is a correlation between the accelerator pump feature, the blip and the FI light.

That is about it.

If any of you have any ideas, please post them up.


Don
 
Drop the fuel on the accelerator pump function, to sensitivity of 80% and the additional fuel level to 10%. Had the same problem on THOR. The FI light will re-set after you turn it off and then back on. Do you have a quick shifter?
 
i am assuming the bike ran fine the last time out ?

did you turn the accell. pump off,and try the bike again ?
 
(GPW @ Oct. 28 2006,18:01) Drop the fuel on the accelerator pump function, to sensitivity of 80% and the additional fuel level to 10%. Had the same problem on THOR. The FI light will re-set after you turn it off and then back on. Do you have a quick shifter?
Greg,
When you said you had the same problem. Did you mean with the stutter as well as the FI light?

Thanks

Don
 
The FI light comes on every time I use my air shifter, stays on until I cycle the ignition. It doesn't hurt anything, it's something to do with the shifter box. I would assume that somehow the PC is killing the ignition at the spot it sputters, but I don't know why. I am not familiar with the acc. pump function, what little I read led me to believe it's for a dry shot. Why do you feel you need it?
 
The FI light will usually come on when the ignition has been interrupted such as riding along and flipping the kill switch off and then back on. I don't know about the acc pump since the busa doesn't have any (acc pumps). I'm not sure if there is a real use for it. Someone here who dynos bikes should know.

Doesn't an air shifter kill the ignition for a split second to relieve the stress on the tranny when shifting? If so then that would explain the FI coming on.
 
(usn04limited @ Oct. 28 2006,16:34)
(GPW @ Oct. 28 2006,18:01) Drop the fuel on the accelerator pump function,  to sensitivity of 80% and the additional fuel level to 10%. Had the same problem on THOR. The FI light will re-set after you turn it off and then back on. Do you have a quick shifter?
Greg,
  When you said you had the same problem.  Did you mean with the stutter as well as the FI light?

Thanks

Don
Just the FI light no stutter...sounds like there is too much fuel combined with your mapping....keep playing with the fuel addition as in lowering it until you can power shift without issue. I only saw the issue with high RPM power shifting. What kind of air mods have you done?
 
(GPW @ Oct. 28 2006,19:12)
(usn04limited @ Oct. 28 2006,16:34)
(GPW @ Oct. 28 2006,18:01) Drop the fuel on the accelerator pump function, to sensitivity of 80% and the additional fuel level to 10%. Had the same problem on THOR. The FI light will re-set after you turn it off and then back on. Do you have a quick shifter?
Greg,
When you said you had the same problem. Did you mean with the stutter as well as the FI light?

Thanks

Don
Just the FI light no stutter...sounds like there is too much fuel combined with your mapping....keep playing with the fuel addition as in lowering it until you can power shift without issue. I only saw the issue with high RPM power shifting. What kind of air mods have you done?
Greg,
Air mods -- K&N, small air box mod and PAIR removed. No air or electric shifting aids.

Don
 
So does everyone agree that it is probably not a clutch or 2nd gear problem? I guess I can answer that question by shutting the acc pump function off and see if it does the same thing. If it doesn't do it, then it is a fuel problem.

Don
 
(Greg B @ Oct. 28 2006,19:39) Start from scratch. Disable the acc feature and report back.
Yeah will do that. It will have to be tomorrow. Headed out on another ride (maybe) with Moondog.

I see you're in Savannah. My wife went to S.C.A.D. What a beautiful and interesting city you live in.

Don

Wife will be going with tomorrow, only in the truck, so I can take my laptop to make adjustments.
 
(usn04limited @ Oct. 28 2006,20:43)
(Greg B @ Oct. 28 2006,19:39) Start from scratch. Disable the acc feature and report back.
Yeah will do that. It will have to be tomorrow. Headed out on another ride (maybe) with Moondog.

I see you're in Savannah. My wife went to S.C.A.D. What a beautiful and interesting city you live in.

Don

Wife will be going with tomorrow, only in the truck, so I can take my laptop to make adjustments.
SCAD is one strange school.
brave.gif
I think they own about half of the city now.
Some great artists there. I should get one of them to paint my helmet or bike one day..........
 
Here is my wild guess.
With the Power Commander installed.
You are exceding the horse power restriction built into the ECU for first and second gears.
(Silly safety concerns.)
As such when you reached that Hp threshold in second the ECU sent a signal to cut power.
 
I think you've answered your own question. You experienced a fault after making an adjustment that for all intensive purposes will not do much for your street performance. Go back to your previous set-up prior to enabling the virtual "acc-pump". I for one do not like that term as it is a carburetor function and not a relevant to Fuel Injection systems. I take it that it is nothing more that a fuel injector pulse width enrichment function to add fuel at specific high fuel demand points in the rider's programmed operational parameters. This may lead to an inability to maintain adequate fuel pressure and fuel supply causing the engine management system to sense the drop and triggering the warning light.
You may have an issue with fuel delivery and fuel subsystems in relation to compatibility with the specific programming of the PCIII. It could be as simple as the fuel filter needing changed or some type of electrical system supply problem to the pump but if you never had the problem prior to the act of enabling the ACC pump then you should focus on finding a resolution through DYNOJET...
Or, it could be a glitch in the programming for 2nd gear fuel mapping yet to be discovered by the R&D team since they compromise in the rush to market.
 
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