Hi,

I have a 2008 ZX-14 with approx 24000KM. The bike is pretty much stock other than the K&N air filter and the Acropovic exhaust.

I live in Calgary which is at 3500 feet of elevation. I went on a trip last fall down to the coast and started noticing some strange behaviours at higher RPMs in 1st and 2nd gear: It feels like I'm running out of gas (kinda). I'm saying kinda, because it's like when you first start to run out of gas, in other words I can hear it, but it doesn't cause the engine to cut out so badly that the front dives or anything.

Some details/things I've tried:
- It only happens at sea level. The problem went away when I got back to higher elevations.
- I rode about 2000 kms at sea level and it always did it in 1st and 2nd but not in 3rd, 4th, etc.
- Level of fuel in the tank seems to make no difference.
- I went through many tanks of gas from different companies / octane and it didn't seem to make a difference.
- The problem disappears as soon as I shift to 3rd.

All of this seems to rule out bad gas? I know the earlier versions of this bike had some sort of RPM limiter in 1st and 2nd gear. Is this the way it worked: cutting off the fuel so you got less torque?

Anyone have any ideas? I've been searching the forums but I haven't found anyone with the same issue...

Thanks in advance!!

Gilles

I've heard of cars having bad coil sticks or maybe it could be spark plugs. Check all electrical connections loose battery posts etc.

A change of altitude wouldn't normally affect electrical connections, would it? Everything works fine now that I'm back to 3500 feet. This only happened at sea level...

Thanks!

Acropovic exhaust.

Slip-ons ? Cat may be clogged. Plugs. Filter. All good starting places. This would be right up Hubs alley. Place your question in the ask Hub section. Cheers & Welcome aboard.

* Last updated by: Romans on 3/28/2010 @ 7:46 PM *

Sounds to me like what Hub described before regarding air/fuel mixture. Perhaps the ECU is confused - not adjusting air/fuel for the first and second gears. That would be my guess.

sounds to me like ur ECU got trained for the higher altitude...ECUs tend to follow trends in the bike for the first couple thousand miles when u get the bike and adapts itself to that environment

You would think the elevation is part of the problem. I suspect the exhaust slash air cleaner to be that sensitive. If the air is thinner, the exhaust and air cleaner running things faster, that says the higher elevation runs nice and lean = Clean throttle.

Subthrottle is ignition related. The advance and gear numbers sort of work the sub smoothing. That has the advance curve running things as the sub is going to act like a vacuum advance with a brain to slow/speed things. The vacuum or throttle in low gears run a lot of [vacuum] load. I would think the gears 1-2 may add to that hesitation or lag of fuel?

I'm shooting in the dark, we have a clean running bike from 3rd on up. I'll guess air cleaner. That means it's a 50/50 swap, we find the stock exhaust and run both back to stock, see if that cleared the problem? Did you have this bike at sea level all stock? Found nothing like you have now?

The air cleaner element can be swapped out and then take a run at sea level. If this did not clear it up, leave the OEM element in, then install stock pipes, you take another run at it.

These sensors follow the atmosphere and do not learn but follow pre-made maps for elevations to follow. They more learn to bring up the other maps to plot the 1atmo. And when it is clear above and stumbles below, there is an air flow problem or speed event; someone is off in the ratio. Everything else is fine.

Did we install these parts recently? Sounds like a lot of miles. Never took a ride at sea level all stock when new? Did it stumble then?

[*] Slip-ons

Yes, Acro slip-ons with the baffle removed.

[*] Cat may be clogged. Plugs. Filter.

Everything is fine here at this altitude and shops here will have a hard time diagnosing something that works... Plugs are new from mid last year and the filter is good.

[*] sounds to me like ur ECU got trained for the higher altitude
Is there anyway to "reset" an ECU? Would a PC V fix this? I guess I'd need a sea-level map?

[*] I'm shooting in the dark, we have a clean running bike from 3rd on up. I'll guess air cleaner. That means it's a 50/50 swap, we find the stock exhaust and run both back to stock, see if that cleared the problem? Did you have this bike at sea level all stock? Found nothing like you have now?

Had never been to sea-level until Sept last year. I live 10ish hours from the coast so it'll be hard for me to try the various combinations. Though an easy one to try would be to put the stock air filter back in.

All the parts went in last summer. That's about 24000 kms = 15000 miles.

One detail I just realized I forgot to mention is that this happens only at higher revs in 1st and 2nd gear... Oups. :-(

Thanks for all the ideas!!!!

* Last updated by: thibaug on 3/29/2010 @ 12:00 PM *

How many "higher revs"?Are you redlining it?Mine will cut out at redline....no matter what gear I'm in.Just like it's "running out of gas".USUALLY....I forget how far I'm going on my revs when I take off and accelerate full on in first or second.It definitely catches me by surprise every time it hits the limiter.I try not to do that of course.

* Last updated by: blue07 on 3/29/2010 @ 1:28 PM *

No, not red lining, starts somewhere around 7000. It doesn't feel or sound like the rev limiter.

Does anyone know what the 1st/2nd gear limiter that was on the 06/07 "felt" like? I wonder if a TRE would help?

Yes-it feels like the bike is running out of gas-just coughs a bit and stops revving/accelerating.Just like like it's stumbling.One thing you COULD do...is check the error code "history".You may have an error code stored in there from when it does it's little deal-then clears after the incident,so you may never realize it's coding at all.That's first thing I would check-which is the easiest and cheapest route to go.You may find what your looking for in the memory.

* Last updated by: blue07 on 3/29/2010 @ 1:37 PM *

How do I get to the memory?

Do you have a Service Manual?

I do. Ah ok, I'll take a look in there.

"Fuel System DFI"......Pg 3-37 to start.

Hmmm... I just seem to get into the "setup" menu. The self diagnosis mode doesn't show up if there are no codes or am I missing something?

No,you're not missing anything.I wasn't positive you could access that menu WITHOUT a DFI error message on the dash.Apparently,we can't unless a DFI error is showing.BUT....your shop SHOULD have a tool that they can use to access that particular menu-so they can check any previous codes without having one displayed.Sorry man-I wasn't sure if you could.It doesn't display a code when it's doing it deal does it?Probably not,or you'd see it when you stopped.They use that function(tool)to check the bike's "history" for codes.ANOTHER possibility would be....(and I don't think it would hurt anything)is to cause a code to display-then you could go in and check for previous stored codes-that could be a way to get in there.You could like maybe try to start your bike at full throttle-you know-flood it?It would most likely flash a code on your display if it didn't start.Then you could access the "code" numbers function-any others in there would be readable as well.

* Last updated by: blue07 on 3/29/2010 @ 2:27 PM *

Ah ok, np! :-) Hmmm, I'll give them a call to see if they have the tool and if there's a "tool hookup fee". I don't imagine a car OBD tool would work?

I don't remember seeing any codes at all, and I'm pretty sure I would have noticed... :-)

I don't think the car deal is gonna get ya in there-but that's the deal they use-something along those lines.She should code at a flooded situation.Just hold your throttle all the way open while she's cranking-for God's sake-if she starts-let up!But I don't think she'll fire.I think she'll code first(just keep cranking till she displays-probably about 5 or 6 seconds)But I wouldn't keep trying to code her that way more than probably twice?Not good for your starter.You could definitely(?) get a code by unplugging something electrical.Just be careful WHAT you're unplugging!

* Last updated by: blue07 on 3/29/2010 @ 2:34 PM *

Here is how the 14 codes work. If she is running bad and the system gets a load of it, there are 3 basic code sets. You have to at least mimic one if not more variables than the fundamental 3 for the dash to show a code. You will not see a code, you hold down both the trip and mode at the same time, key on.

If it reads, "English - Bla bla" then no code present. Therefore, no codes or else it would flash (((FI))) on the dash as soon as you turn the key on.

TRE will only make it worse you are not tuned for a tre type move. Put the baffle back in, when you go to back down to sea level. Leave the air cleaner alone now > Since you brought new information about the running/tuning part of the pipe...

"Yes...' 'baffle removed."

* Last updated by: Hub on 3/29/2010 @ 3:07 PM *

Thanks for all info and help!!!

If you would, let us know what the outcome was. I'm curious to know.

Sure! It'll be a while before I'm back at the coast though, probably June or July. I'll try using a stock filter for the trip and I'll bring the baffles with me.

* Last updated by: thibaug on 3/31/2010 @ 12:41 PM *

Did the Idle drop down when you were having the problem.

> Did the Idle drop down when you were having the problem.

Nope, no changes in idle speed.