Shane661
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posted November 25, 2009 04:48 AM
 Edited By: Shane661 on 25 Nov 2009 12:52
- IAT, Intake Pressure Sensor, Power Commander Issues? -
I had a very interesting dyno experience yesterday. At high rpm (9-11k) the bike would alternately run rich or lean (13.6:1 to 12.3:1 on the ends of the spectrum). The odd part was that adjusting the power commander for the affected rpm range did not seem to net much, if any effect, even when going as much as 30 points in the cells. This was for WOT mapping only.
When I got the bike home I started investigating. The bike had been sitting fairly disassembled for about 6 weeks, and I threw it together on Monday night. So, I wanted to eliminate any re-assembly gaffs as a cause.
Well, I found two things:
1) Left airbox inspection plate bolts were not tightened down
2) #1 Cylinder velocity stack rubber boot clamp was not installed.
I can see where perhaps IAT may have gotten some odd readings due to airbox seal being compromised. However I don't think that would only cause an issue at high rpm.
The one that has me more interested is the velocity stack sealing on #1. I wonder if this potential leak could be affecting the intake air pressure sensor at high rpm? I am still not sure why we couldn't see a change when adjusting the power commander cells at high rpm. It seemed to respond fine through the mid range.
Any ideas? The dyno sniffer seemed to work fine on a 636 that went on the dyno after me. I am not at all hesitant to blame myself here, but I want to understand what is going on. There may be several factors contributing.
Shane
  
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Shane661
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posted November 25, 2009 12:47 PM
Edited By: Shane661 on 25 Nov 2009 20:49
I'll be sure to post what I find, since this subject is also apparently baffling to those other than myself. 
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KZScott
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posted November 25, 2009 01:04 PM
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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Shane661
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posted November 25, 2009 01:09 PM
Edited By: Shane661 on 25 Nov 2009 21:10
Short of knowing all of the formulas and tables in the ecu, I imagine you could control the iat ouput and pressure sensor outputs via a potentiometer. Then you could simulate how the ecu responds to temperature and pressure changes.
In my case, I'd just like to get the bike back on the dyno before Saturday...but it might not happen.
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entropy
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posted November 25, 2009 01:43 PM
keep after it, Shane!
i love seeing someone more obsessed than I am puzzling stuff out.
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Shane661
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posted November 25, 2009 01:44 PM
Edited By: Shane661 on 25 Nov 2009 21:45
Good news everyone! I will have the bike back on the dyno Friday. 
Sorry to keep you guys on the edge of your seats like that; I know the suspense was killing you! 
Karl, I could barely sleep last night because this was on my mind. I will figure it out.
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Shane661
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posted November 25, 2009 01:46 PM
Edited By: Shane661 on 25 Nov 2009 21:49
Still, I would like to know if anyone has any details on the IAT and pressure sensor function. Specifically how much they can impact injector duty cycle...
If that Intake stack was fluttering at high rpm I wonder what that strange pressure harmonic might cause the ecu to do?
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2000redrocket
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posted November 25, 2009 03:47 PM
on our zx12s i would say the bike is running off of the rpm vs tps maps. when doing a wide open log on the street to adjust afr i add fuel to the density map (uses the map sensor) i get nothing different. i use the tps vs rpm maps to make a change at the track or dyno. maybe your tps has a "bad spot" at full throttle? cause and effect dictate you go again with all the stuff straightened out. maybe watch the voltage at the tps and map with a logg or meter to see if it jumps around.
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Shane661
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posted November 25, 2009 04:06 PM
Edited By: Shane661 on 26 Nov 2009 00:08
Tomorrow I am going to make sure (again) that the tps is set properly with the PC. I am also going to try to fashion something to allow me to use the LM-2 to verify the dyno sniffer.
On that note, how does the tps function? What can impact it's settings?
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2000redrocket
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posted November 25, 2009 04:19 PM
tps voltage feedback tells the ecu how much throttle you pulled and can use that and how fast the rpms are rising to determin the load on the engine. if it waivers while you are wide open it may think you backed off and cut back fuel. that or some other sensor having a glitchy reading. under the dyno pull.
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Shane661
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posted November 25, 2009 04:21 PM
I guess what I am asking is, what can cause the tps cal to go out?
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2000redrocket
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posted November 25, 2009 04:29 PM
i guess if you take the cables off and it snaps closed (the trottle cables) it could come to maybe damage. but if it moved one would think it would run bad all over. if rpms are rising while pinned and the voltage waivers it will tell the ecu to change the dewll time on injectors if it moves enough.logg tps durring a dyno pull. that will eliminate that anyway.you can log map also. maybe ridge will chime in.
is the fuel system eliminated like sucking air, blown internal line, etc?
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Shane661
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posted November 25, 2009 04:43 PM
Edited By: Shane661 on 26 Nov 2009 01:12
I am going to the dyno on Friday. I am going over the bike thoroughly tomorrow.
When you set the tps to the Power Commander, is that setting then stored in the Power Commander itself? Do map changes affect it at all?
All I know now is that I had an untightened frame inspection plate, and the rubber boot on the #1 velocity stack had nothing clamping it to the throttle body. I am sure these two (particularly the latter) may have caused some anomalies.
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