Kawasaki World banner

1 - 13 of 13 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
Hello all,

I'm reaching out to the forum for some help with nailing down a temperature-stable idle RPM that I can 'set and forget'. Here are the specs.

2002 B1 with 9000 miles. Never down, never abused, no major service or repair items, but has always shown these idle issues to some degree. I've just installed a PC3, a full Hindle 4-2-1 stepped pipe and K&N filters. I'm running the appropriate map for my setup from Dynojet. I live at sea level and experience no elevation changes while riding.

I've removed and thoroughly cleaned the throttle bodies. They are accurately synched and set to service manual specs. A new set of OEM plugs are in as well. Oil and filter changed 500 miles ago.

KLEEN air system is out and the airbox hole has been sealed. I've confirmed no vacuum leaks by using the starter fluid method.

No FI light, no fault codes. In short, all the basic stuff has been attended to. Bike runs very nicely, pulls pretty cleanly from idle. Maybe a nit or two to pick with the fuel curve at RPM here or there, but overall I'd say so far, so good.

Here's the problem: When I raise the idle speed to say 1250, it rises to about 1400 when the engine temp reaches the upper third on the gauge. It's difficult to accurately describe, but the bike just doesn't "feel right" at that high an idle either.

When I go down low to 950 (definitely preferred) the idle and throttle response are perfect , everything is just right...until the temps lower to the middle of the gauge after a steady cruise or short engine-off period....then it will stall on restarts or by rapidly shutting / chopping the throttle. However, allowing it to reach max heat returns it to good manners.

Splitting the RPM difference to 1000 -1200 sets up the classic sine-wave lopey idle and also degrades throttle response. I do understand and appreciate the effects of cam overlap, headers, scavenging, etc. and respect there will always be tradeoffs, but the idle flow characteristics are clearly not properly resonant in that RPM band. I'd rather avoid that result.

There seems to be an underlying problem and my best working hypothesis right now is that the coolant temp sensor might be at fault by sending the ECM a shaky engine temp signal.

Am I on a reasonable diagnostic track here...or is that 1000-1200 rpm idle range just one of those things that comes with the package and I'll have to learn to live with??

Thanks for your time.
 

·
Registered
Joined
·
1,664 Posts
has the throttle control position been set on the pc3..Also check/adjust the tps on the side of the throttle bodies. You might need more mapping on the pc3.Keep in mind that the cooler an engine runs the richer the fuel mix and the hotter it runs the leaner the fuel mix.After you do what I have mention and have the same results try going up or down on the fuel mix in the bad cells in the pc3 mapping.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #3
Thanks for your help, zx12mark.

Yes, I've reset and zeroed the TPS via the PC3 software. I've also tried a few of the other maps and tried to potentially narrow the issue down by entering their data into Excel for comparative graphing & analysis against the Hindle map.

I haven't looked at the TPS unit itself as yet, though. I'll do that and report back ASAP.

In the meantime, how do I identify the bad cells in my map? Are you referring to the 500 & 1000 rpm cells across the board?
 

·
Registered
Joined
·
239 Posts
You have the classic loopy idle that this bike shows when a full race system is fitted, this is because the mixture at idle is lean.

You need to richen the mix at idle by increments of 5 units until you have a steady idle and then fine tune if you like after you have a good base figure.

Get your map up on your computer and then just manually adjust the figures at idle and at 0 throttle by adding 5 to the unit you have.

Save the map and upload it to the bike and try it out.
 

·
Registered
Joined
·
4,277 Posts
These bikes always run different from a cold start to proper temp. If you let the bike idle from a cold start on the fake choke, you'll notice that once it hits a certain temp the idle will automatically go up. They also run a bit higher when they get hot. I've always been adjusting the idle when needed. It's as easy as reaching down and twisting the screw.

Being fuel injected, it runs different till it gets to temp. They also run pretty lumpy sometimes. It's a ZX12...:thumbup:
 

·
Registered
Joined
·
11 Posts
Discussion Starter #6
Hi my12r,

I understand where you're coming from - it might be time to simply live with constantly twiddling the idle screw.

It may indeed be the reality, as inelegant and unsatisfying a solution that it may be. I intend to exhaust every reasonable solution before I submit to that though.

After owning and modifying several carbureted bikes in the last 25 or so years and having had to tune out many driveability issues with engines & carbs the old fashioned mechanical way - i.e. effectively by trial and error with setting jet needle positions, float heights, etc. - I consider having a real FI bike quite a luxury.

Now, having said all that, with its ability to effect changes and remedies quickly and concisely I expect to achieve more and better from an electronic engine management system. I do appreciate and embrace the limitations of an open-loop system, however. No MAF and O2 sensors = time consuming & generally harder to do.

But it's obviously NOT impossible. Others seem to have solved the idle & tuning issues with aftermarket pipes just fine. There is clearly a zone where the engine is 'happiest' at close to 950 rpm.

The problem for me is keeping it there through a range of operating temps. It seems that should I be able to find / create / send the right set of sensor values for the ECU it would ultimately solve the issue...unless I'm way off base here, gents...
 

·
Registered
Joined
·
1,664 Posts
I have always had to run my idle at 1300 rpm.Oil pressure is better like that anyway.
 

·
Registered
Joined
·
840 Posts
These bikes always run different from a cold start to proper temp. If you let the bike idle from a cold start on the fake choke, you'll notice that once it hits a certain temp the idle will automatically go up. They also run a bit higher when they get hot. I've always been adjusting the idle when needed. It's as easy as reaching down and twisting the screw.

Being fuel injected, it runs different till it gets to temp. They also run pretty lumpy sometimes. It's a ZX12...:thumbup:


Ha ha ha, couldn't agree more..... fickle things lol!
 

·
Registered
Joined
·
4,277 Posts
If you figure it out, there will be quite a few 12 owners here who would be happy campers. In the 14 years the bike has been in existence, it's been a fight to find and maintain a stable idle throughout the temp range. It's in part because of the open loop system, in part cause the bike was built to hit damn near 200mph, not stop and go traffic, and in part due to compromise. There are many changing variables that need to be taken into effect. You could do like kzscott and build your own ECU and make it a closed loop system, if you're into that sort of thing. Motorcycle FI is primitive by comparison to automotive. Very basic, and in such, there are limitations. I wouldn't go so far to say it's impossible, but economical, I dunno. They are getting better at it, but, until the market shifts from "holy shit that's a lot of power" to "hey, why not make an overall good performer with economy and stability", there's gonna be compromise.

FI is indeed a luxury. In these bikes it's also a nightmare at times. Very touchy bikes. They ain't really made for idle. They made to haul some serious ass in 1 trip. Give it a go. I'd be curious to see if some fresh eyes find something most have overlooked. The bike "should" idle smooth at 1,050rpm +/- 50. With the cams and open loop, not sure if that can be achieved.....unless your screen name is hubz14....:lol:
 

·
Registered
Joined
·
36 Posts
Never played with my idle speed, bought the bike with a full akropovich system and sure it can be a bit lumpy when warming up, but it smooths out fine towards the first or second temp increment on the gauge. My thinking is, the bikes a lump without auto choke, let it warm up and aim to get it smooth at operating temp, after all how much riding do we do at idle with a cold engine? Just my opinion and not a criticism, good luck with smoothing her out, and as said before, if you figure it out, let is know :)
 

·
Registered
Joined
·
11 Posts
Discussion Starter #11
All,

Many thanks for the help and replies. Much appreciated.

I've looked at the TPS and found it out of spec @ WOT. I'm showing a consistent 4.10 VDC, service manual specs 4.61 or close. Idle was 1.07.

Despite the TPS WOT voltage issue, I took creedxup's advice and richened the idle mix, settling at +10 points across to 40% throttle. I also did the TPS mod, locking in @ 1.15. Idle speed was set at 1050 rpm, confirmed using the PC3 software. TPS was zeroed once again.

Richening the idle mix definitely helped calm down the lope. As expected, the idle speed rose about 150 rpm at max temp, but critically the lope was again fairly calm as the engine temps went down after a steady cruise / engine off. It's still there, but much less so.

The TPS mod proved quite effective as well. I found a welcome increase in driveability and road manners. Throttle response was very crisp. Nice.

So far, so good --I feel that I'm on the right track. I'll increase the PC3 rpm resolution and continue tweaking the idle mix and see how that goes. I'll order a new TPS unit as well.

Thanks again, gents. More to come.
 

·
Registered
Joined
·
239 Posts
It's good that you feel you're getting somewhere, but unless you have other problems with the fuelling, you only need to adjust the units at 0% and possibly 5% and at 1000 revs up to possibly 1500 revs, altering the other figures for percentage throttle opening at idle may make the bike bog down when you try to pull away.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #13
Creedxup,

I hear ya. It seems to respond well with no stumbling so far, but will try dialing it back in that range to see how it goes.

I'm enjoying the tuning process and believe I'll eventually close in on a working solution, but after reading the PC V & Autotune upgrade threads I'm thinking that's the way to go for best results. No substitute for that level of feedback, logging and control.

It would be great to see all the sensor outputs in real time with something like BikelTech's diagnostic OBD module, but as I'm sure you know there's no diag port on the B1... :-(

I did see a long thread on a different board re ECU hacking and the OP had in fact identified the ECU sensor output pathways, but it doesn't look like anyone has gone any further with it....
 
1 - 13 of 13 Posts
Top