| Author |
Message |
    
Gunut75
| | Posted on Wednesday, January 21, 2009 - 12:44 pm: | 
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I would like to know what system of fuel injection my 05 XB uses. Speed density, or mass air? When it goes from closed loop to open loop, or vice versa, what causes this (i.e. engine temp, crank speed)? I have a basic knowledge about fuel injection, and know how it works. I just want to know what Im dealing with for future reference. Thanks in advance for any input on this! |
Aptbldr
| | Posted on Wednesday, January 21, 2009 - 01:16 pm: |
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Wish I had a magic search-string to answer your request.
Information you seek is here, grasshopper, but it's embedded in floods of obscurity.
Check-out ecmspy.
http://www.ecmspy.com
This is most amazing software.
Its PDF manual was a clear explanation to me. |
Buelltuner
| | Posted on Thursday, January 22, 2009 - 07:15 pm: |
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fuel system type is Alpha/N. throttle position over rpm. closed loop is reached by ET and RPM/TP. it is a glorified carb. No Map sensor, No mass air, only TPS,ET,IAT,O2,CMP. |
Aptbldr
| | Posted on Friday, January 23, 2009 - 07:06 am: |
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What's "Alpha/N."?
What's CMP?
Do I have the others?
ET-engine temp, RPM-crank revolutions/minute, TP-throttle position, IAT-intake air temp, and O2-exhaust oxygen |
Kalali
| | Posted on Friday, January 23, 2009 - 01:31 pm: |
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I think CMP is Cam Position Sensor. |
Buelltuner
| | Posted on Friday, January 23, 2009 - 08:35 pm: |
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Aptbldr, CMP=cam position sensor, Alpha/N is a throttle position and engine rpm based EFI system. We Buellers are not blessed with an EFI system like that on a Harley. We have to work with what we got. Yes we can get them running pretty good, but carbs can run good too. Why have good when we can have GREAT! |
Gunut75
| | Posted on Monday, January 26, 2009 - 12:09 pm: |
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OK.... so that would explain the subtle differences in tuning for each individual bike. Minor variations in each bike would have significant effect on tuning results. Am I right?  |
Gunut75
| | Posted on Monday, January 26, 2009 - 12:36 pm: |
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I learned FI from tuning and modifying a 87 Mustang GT, with a speed density system. That particular system made adjustments in timing, fuel delivery, etc. by monitoring the exhaust oxygen, crank speed, and engine temp (primarily). Hence, the computer would adjust to mods (intake\exhast\timing\etc.) on its own. So (Buelltuner) what youre saying, is that we have a preset map that only delivers a given amount of fuel\spark advance based on given values of throttle position\engine temp. It does NOT self adjust to performance mods. This is why we have to ECMspy every time we change something that will effect engine output. The mapping has to be changed to compensate for more air\more fuel etc as to not lean out or richen the mixture. Is this correct? |
Kalali
| | Posted on Monday, January 26, 2009 - 01:32 pm: |
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In a nutshell, actually the DDFI2 system (X1, S1, etc.) works both in Open Loop (using preset maps) and Closed Loop (learning via O2 sensor) modes. The Open Loop mode is during idle and WOT and CLosed Loop is in the steady state 2-5K RPM range mostly constant throttle position. The ECMSPY allows you to change the maps and a whole bunch of other variables like Air Fuel Value, Throttle Position Sensor calibration, etc. |
Buelltuner
| | Posted on Monday, January 26, 2009 - 01:43 pm: |
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Gunut75, Yes that is right. It does learn though through the O2 sensor but, this does not net a recalibration suitable for a new engine setup. Because changing an exhaust for example will change fuel ratios at different parts of the map by different amounts. So what the O2 sensor learns and applies at one spot does not satisfy the needs of another. |
Gunut75
| | Posted on Monday, January 26, 2009 - 02:02 pm: |
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Kalali, youre right, but, from what I've gathered, our ECMs wont adjust to the amount of extra fuel needed, or more air coming in on their own. |
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