stevew
Parking Attendant
Posts: 12
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posted June 21, 2009 03:56 PM
PCIIIUSB Setting Throttle Position
I have been using a PCIII USB on my 08 ZX-14 for over a year now with one of Brock's maps. All has been and continues to be working well with the Brock SMEG.
Since I installed the PCIII just after purchasing the bike new, I thought I would recalibrate the open and closed throttle position settings again using the PCIII software in case it has changed after a year of riding. What I have discovered, is that the closed position value differs between when the engine off and when it is idling.
For example, when I leave the engine off and power the PCIII with a 9V battery, I end up with the following values – 5,524 closed throttle, 24,352 full open throttle. When I perform the same test without the 9V battery, but with the bike on and idling, the closed throttle value drops to 5,026, the full open thottle value does not change materially.
I am trying to understand why this difference exists. A 500 lower closed throttle value when idling is approx a 2.5% difference. If this has something to do with the idle setting, I would expect the value to increase and not decrease. FYI - my idle is set to approx 1,050 rpm.
What value should I use to calibrate the PCIII? My gut says to use the idle closed throttle value of 5,524 in my case, but I am trying to understand why I am seeing these different values and the underlying cause.
Any ideas?
  
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smokinZX14
Needs a life
Posts: 10197
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posted June 21, 2009 04:05 PM
I set mine while it's running so i really don't care what it reads when it's not running ..Can't drive it with the engine turned off anyway ..
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Smokin Performance Cycles..
Tampa Bay , FL .. Brocks Performance Dealer ..
Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
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dubious
Needs a life
Needs more time to ride!
Posts: 8442
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posted June 21, 2009 04:13 PM
your seeing differences due to secondary shaft opening the prinary shaft prior to start up.
Alot of people don't realise the secondary shaft has a cam on the end of it that opens the primary approx 10% when the secondary is wide open. The ecu does this so it will start and stay att high idle if the engine is cold.
Like Lee said set it running, and engine warm.
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natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
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FastestBusaAround
Needs a life
I eat Fish...
Posts: 7889
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posted June 21, 2009 08:49 PM
It should read zero when idling, or engine off with a 9V battery...and that upper value of 24K+ on WOT. You can do it at engine idle, but not a good idea to WOT in neutral with no load...IMO.
If you set it with the 9V battery engine NOT running, it will be just fine. I've done many of these on many different bikes with no issue, engine off. You should warm up the engine to get the fast idle OFF before you make your adjustments though, as was mentioned above.
The upper range will alway vary a few hundred RPM, which is nothing to be concerned about.
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FYYFF!!!
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stevew
Parking Attendant
Posts: 12
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posted June 22, 2009 10:32 AM
Great, thanks for the quick reply guys. I indeed went ahead set the closed throttle position at idle after the engine warmed up, but was just curious about the discrepancy. I happened to be doing a PCIII firmware upgrade using the 9V battery when I began to do the throttle position setting. If I had not been doing this, I would have never noticed the difference.
Thanks again for the explanation...
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