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Discussion Starter #1
Hey guys I'm having an issue at 3500 RPM's where at pretty much no load the bike starts surging... we noticed it on the dyno and now I see it happening on the street. I think it may be that the voltage is off on the new throttle bodies I just installed what do you think????
 

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mmmmm.....3500 rpm is the point that the ECU cuts fuel during off-throttle, which is what leads to the decel pop that's so often discussed and attempted to circumvent.
 

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Discussion Starter #3
mmmmm.....3500 rpm is the point that the ECU cuts fuel during off-throttle, which is what leads to the decel pop that's so often discussed and attempted to circumvent.
Yeah but this is not that issue.... It's real strange. It's when your on the gas real light input.
 

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With sensors sending signals to the ECU and other electronic add-ons such as the PC, there might be some signal confusion causing irregular fueling at that point. Your idea about voltage at the throttle bodies may be in the ballpark. A build-up of excess fuel causing a surge and then followed by a slight starvation would indicate some fueling issue. Might be a little fat right before that point.
 

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Discussion Starter #5
We tried major Changes to fueling map and there was no difference on the surging.
 

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Is it the same spot/rpm range everytime as in if u held it light throttle at 3500? everything? I would think it is electrical if it is that consistent. Ohm ur coils. It's ez to do and eliminate them from being an issue.
 

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Mine does the same, the PC5 and a map from fuel moto has it almost gone, but I notice it from time to time. I try and stay away from that rpm when riding

Someday when I get a real tune on a dyno I'll ask what they see in that area and see if anything can be done. I doubt it though.
 

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Is there any way you can put a voltmeter or oscilloscope on the injector connectors? You would then see if the signal is changing in sync with the surge.I think Hammer is on the money. I would be looking very carefully at those new throttle bodies. Are they supposed to be grounded? Are the connectors perfect - a small high resistance in a connector might be throwing things off. Is there a sensor that is not right? Leaking vacuum hose? The PCV corrects the ECU, but if the ECU is sensing something wrong the PCV will not correct that problem. You need to know what the signal to the injectors looks like so that you can figure out what is causing the feedback loop.
 

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I'm no electronic Einstein, but I tend to suspect the simplest cause for any issue. The factory ECU dicks with things at 3500 and despite PCs, maps and other mods, that's still in there.
 

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Mine start like stuturing about 3 grand and it would quit and accellerate.It would quit doing it.Then I changed the Brocks race map and put in the street map,same thing.And the last 2 times it didn't do it.It's the only 2 times this bike has ever done this.Reminded me of a carbarated bike.Next week when I get it dynatuned I'll tell the guy what it did.Changing maps made no difference.
Craig
 

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Discussion Starter #12
Guys thanks for all the great input for sure. I need to check the voltage but you need a special wire harness jumper to do it.. My dealer said says they are busy and it will be two weeks before they can even look at it. Also I had my ECU reflashed by dynotronics so I'm wondering if that might have something to do with it? It's always the same conditions when it happens. My thinking is if it's a TPS voltage issue what is it doing. I don't have the secondary flies in there anymore so how could that do anything? My engine builder changed the ground location from the bolt on the coolent tank to the bolt on the front sprocket cover so I'll change that back and see it that may be anything but I don't think so....
 

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Discussion Starter #13
Well checked all grounds and moved the PCV ground and nothing. I checked the volts on the main and sub tps and they were right on. This reminds me of a pick up truck I had and it was the same thing in over drive with little to no load it used to make a driveline noise and jerk forward.. This is the same thing and I'm wondering if after the super sport head and degreeing the cams it's kind of the same deal. What do you think?
 

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Quinton Phuckin Tarantino
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Just curios but did you have your cam degreed for more power up top or for more midrange ? I also don't remember if the 14 has a cam sensor or not , this could be the root of your problem though. Degreeing the came will change the intake velocety and change vacuum patterns through the rpm range witch could confuse the ecm .
 

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Discussion Starter #15
Iron for more mid and top. the gaind start at 6500 to 11500. I'lI took the cams out and didn't see a sensor anywhere so I'm thinking it doesn't have one?
 

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Try reloading your fuel map and recalibrate your throttle position. Make sure the bike is warmed up when recalibrating your throttle.

Do you have a lot of free play in your throttle? If its real tight (no play) make sure zero throttle position is actually a very slight twist of the throttle and not as it sits.
 

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Discussion Starter #17
Big blue can you check the voltage out put without the wireharness from Kawasaki? I don't have the jumper kit they sell. I have a little bit of play where when I brought it into my engine guy there was no play. But he installed new throttle bodies....Maybe if I take out the little bit of slack? I'm kinda grabbing for straws. I unpluged my Bonnie Pro and no changes.
 

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Quinton Phuckin Tarantino
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Big blue can you check the voltage out put without the wireharness from Kawasaki? I don't have the jumper kit they sell. I have a little bit of play where when I brought it into my engine guy there was no play. But he installed new throttle bodies....Maybe if I take out the little bit of slack? I'm kinda grabbing for straws. I unpluged my Bonnie Pro and no changes.
I think blue is talking about setting the tps with a power commander , correct me if I'm wrong but you had yours reflashed . You might try to set the idle screw all the way out till its not touching the throttle shaft and taking an ohm reading on the tps from the center lead on the tps plug to one of the side leads then the other . One should read about 0 ohms the other should read about 10k ohms ( I think ,but I can check if you want ) . Open the throttle wide and these values should be opposite of the plates closed .
As far as the cam timing goes if you are set to more toward the top end you will not move as much air at low end and you will probably run rich at low end if your map has not changed since you did this mod . I hope I was clear enough to understand . O BTW am I correct in assuming you had a reflash done and a power commander ?
 

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Discussion Starter #19 (Edited)
I think blue is talking about setting the tps with a power commander , correct me if I'm wrong but you had yours reflashed . You might try to set the idle screw all the way out till its not touching the throttle shaft and taking an ohm reading on the tps from the center lead on the tps plug to one of the side leads then the other . One should read about 0 ohms the other should read about 10k ohms ( I think ,but I can check if you want ) . Open the throttle wide and these values should be opposite of the plates closed .
As far as the cam timing goes if you are set to more toward the top end you will not move as much air at low end and you will probably run rich at low end if your map has not changed since you did this mod . I hope I was clear enough to understand . O BTW am I correct in assuming you had a reflash done and a power commander ?
Iron I had her custom tuned after all the work so she is all good there. I was going to check the voltage output on the TPS sensor the book says it should be 0.63 or slightly higher at idle and 3.91 fully opened? does that sound right? I don't know if I can get a wire in the back of the damn plug to check it is the only issue. I never thought of looking at it on the PC will that do anything? My reflash was to the ECU and then had the custom tune.
 

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Quinton Phuckin Tarantino
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Iron I had her custom tuned after all the work so she is all good there. I was going to check the voltage output on the TPS sensor the book says it should be 0.63 or slightly higher at idle and 3.91 fully opened? does that sound right? I don't know if I can get a wire in the back of the damn plug to check it is the only issue. I never thought of looking at it on the PC will that do anything? My reflash was to the ECU and then had the custom tune.
That is a voltage test for the tps ,what I was talking about was a resistance check . You can do a voltage check by either probing the wire with a Sharp meter lead (not suggested) or sometimes you can fit some small paperclips down into the back of the plug. Making sure you don't cross them ( I use the coated paperclips and strip them back like you would a wire ) . There is a program in the dropdown menu in the pc program that you can set up your throttle I can check later to give you a rundown of the process if you want . I'm not in front of a computer right now .
 
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