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Discussion Starter #1
I bought a 04 gsxr 600 last fall. It has a Power Commander III USB installed on it. It has an HMF full exhaust from what the sales guy told me.

Here is the problem. When I start out from a dead stop, the bike acceleration stutters in the really low RPMS. By "stutters" I mean the bike accelerates unevenly, slightly jumpy, and definitely not smooth. As soon as I hit 2500 I get a big boost in acceleration. This happens every single time. In higher gears and at higher speeds my bikes acceleration seems normal with a steady increase in speed according to how much I turn the throttle. Other times when I try to speed up quickly the acceleration feels flat, where I feel like I gain very little speed when increasing the throttle. My bikes idle also seems off, sounding almost rhythmic and uneven while my friends bikes idle steady.

From reading up this sounds like it could possibly be a problem with the tuning on the Power Commander. I do not have the software on my computer and I wouldn't know the first thing about mapping it out myself. A local shop professionally tunes bikes on a dyno but its going to run me about $250. I am willing to put the money down if this will solve my problems.

So, to all you guys with experience, does this sound like a problem with the PC, or does my bike just need a tune up? Does it sound like a more serious problem? Any info/advice is appreciated.

Sorry in advance if I left out any important information
 

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Rhythmic idling makes me think TPS or idle air bypass issues. I would find a FSM and take a look at those and the troubleshooting section.

I don't know much about PCIIIs so I suppose the 2500+ stutter could be that. Not really tuned down that low maybe.

A 600 doesn't have a bunch of torque, so you're sure you're not lugging it when it gets flat trying to go fast?

And 2,500 seems about the slip point when taking off so you should be above that most of the time. That's right around the low end of most bikes (I4s or smaller displ. in gen.) usable rev range anyhow.
 

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install the "ZERO" map and see how it acts. There could be a problem with tuning of the PC3, or like YZFHEFF said, it may be in another area entirely. The easiest way to see if it's in the PC3, is to disconnect it and re-connect the factory connectors. If it clears up your problem, you need to re-map and calibrate.
Also... that bike is not going to make good power that low in the rpm range anyway. But it does sound like there is a problem, none the less.
 

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Discussion Starter #4
Thanks for the advice so far.

I got my bike hooked up to my computer with the PC software running. Here is a screenshot of the map.



I don't know about the air filter, but I know the exhaust is not stock.

On a cold start, the bike is idling rhythmically between 900 and 1100 rpm. The PC software shows the RPMs going from the 900s to the 1100s back and forth. Once the bike warmed up a little I was idling fairly steady in the 1200-1300 range.

I forgot to mention before that some of my more experienced buddies mentioned that they catch a strong gas smell when riding behind me leading them to believe my bike is running rich.

Does the map above seemed screwed up to anyone that is familiar with PC maps? I notice some larger numbers around the 2750 rpm mark, and thats about the time my bike gets an acceleration boost.

As far as installing the zero map, or any of the other packaged maps, will an incorrect map mess up my bike? I heard maps that run too rich or lean can really screw up things internally.

Hopefully this is just a bad map and not a sign of something more major that is wrong with the bike
 

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Well, I gotta say that it should be apparent to anyone looking at the map to see, that inside of a 500 rpm range in the same throttle position, the fuel numbers can change 19 or more points at any given time. Also, the 10 point increase at 1500 rpm is definitely a bleed-over adjustment to you idling problem. (Kinda like a fuzzy logic thing going on.)
You need to install the "ZERO" map and see how it runs. The next thing you need to do is look for the throttle position while idling and let us know where that is.
To me, that map looks like some idiot was playing with it and does'nt know what they were doing. (Or a map that has been taken from the web)
 

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Discussion Starter #6
I installed the zero map and it definitely seemed to smooth things out on a start from a dead stop. The choppy hesitation in the throttle at low rpms seems to have gone away. I only took the bike around the neighborhood a few times to test out starting and stopping so I am not sure how the bike will act up to speed in higher gears.

At idle, the throttle % is reading 0 on the PC program. rpms are in the steady 1200 range. A quick short twist of the throttle will get the % readout to 4-6. The idle on startup seems somewhat better, but the bike was still warm when I re-started the bike after letting it sit 20 min. I did notice a slight rhythm to the idle, and noticed my headlight pulse a bit in time with the idle.

Any advice for what to try next? Can I run my bike normally on the zero map without harming it?

I really appreciate your help thus far.
 

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Ok, You won't hurt anything running on a "zero" map. What that is, is a "ZERO" change to your current map in your ecm. Basically, you're running your stock fuel map.
The slight blip of the throttle and only netting 4-6% kinda bothers me. That's telling the computer not to give it enough fuel and timing. (assuming the tps is reading low) What you need to do next is access the dynojet PC3 screen again (while running and at operating temperature) and click on "tools" or Power Commander Tools" (forget which one) and pull up throttle position reset. Once the added screen pops up hit "reset". Let idle for about 10 seconds, then quickly pull the throttle to "FULL" throttle and hit the rev-limiter, do this once more to verify the WOT setting. Save the setting by clicking "ok" and your throttle position sensor is calibrated.
As for your choppy idle, you need to synchronize the throttle bodies and that should fix any problem you're having with the choppy idle.

Once you have verified the TPS position is correct, see how the bike runs. It's more than likely to be a tad rich on the top end @ WOT. The biggest area of concern will be the "cruise portion of the map. Cruise refers to very light throttle (2-5%) at any given rpm range... most often around 5-8k rpm. Basically, if you're holding your speed on the highway (60mph or so) and it seems to miss or stutter, you will need to make an adjustment to that portion of the map.
Keep us posted.
 

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Discussion Starter #8
Here are two short videos that might help shed some light on my situation.

The first video is a cold start up of my bike. You can hear the idle and see the rpm read out on the PC software. It can be seen here:

YouTube - 2004 Suzuki GSXR 600 idle problems

The 2nd video shows the bike idling at running temp after I took it around the block a few times. I bring up the throttle position window and show the values that were currently set on the PC. You can see the 2nd video here:

YouTube - 2004 Suzuki GSXR 600 Power Commander Throttle Position Sensor

I noticed that the closed value was higher than the current value at idle. I followed the instructions given by Papa Rocket for resetting the throttle position information. Now I get a much more responsive throttle % reading when I crank the throttle. One thing I notice now is that the throttle % at idle is now jumping from 0-2% as opposed to a constant 0% before. Would that be caused by my uneven idle? The light column on the PC now flickers between the bottom 2 lights as opposed to only the bottom light staying on at idle.

I feel like I am making some progress. The acceleration issue definitely seems smoothed out. I am waiting for the rain to stop to get the bike out on the highway at higher speeds to see how it does.

As always, any info or direction is appreciated
 

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Now go back into the throttle position screen and just highlight the "closed" numbers in the pop-up window and type in 8000 and see how the throttle percentage looks then.
Next you can try to re-install your map that you originally started with and see how it runs with that map.
Once you have the original map installed, you can go into the map and change the values on the "odd ball" numbers such as... In the same % of throttle range, you can change them something close to the other numbers next to them and that'll smooth your power delivery a ton!
 

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It's been almost 10 years since the original post, but I am trying to fix the same exact bike, year and all, bike with exactly the same problem with stock ecu. Jpro, how did you end up fixing that issue?
 
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