CAJ Innovations Forums - Pressure-Altitude Sensor issue

Quattroporte

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Pressure-Altitude Sensor issue
05/03/10 at 08:02:43

I have a my15m on a 2004 V11s. To get the initial map I got for it to work, I really had to increase the mixture quite a bit.

I noticed my barometric pressure showing 922mb when hooked up to the controller which converts to aprx 27.22 inches Hg. I know that sound low unless I was in the middle of tornado so I called up the Airport ATIS to get a decent reading and its 29.93 (1015mb) in which Los Angeles airport is basically sea level like where I am.

Would this explain why my map was so far off?

The maps have the following set in the program:

MyECU Cfg Pressure=249mV,121mB,4751mV,1060mB

I pulled the stock sensor (smaller one)from the wm15 and installed it.

Question is, Do I have the wrong settings with my sensor?

Thanks for any suggestions...

Charles

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raz Senior Member Offline Guzzi 11OO Sport, My16MkV, Innovate LC-1 Posts: 373 Stockholm, Sweden Gender:	Re: Pressure-Altitude Sensor issue Reply #1 - 05/03/10 at 08:26:06 As to why it reads so low I have no idea but if I recall correctly (1024 mBar is 100%) that should produce some 10% too lean mixture so you may be on to something.
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Quattroporte YaBB Newbies Offline I love MyECU! Posts: 39	Re: Pressure-Altitude Sensor issue Reply #2 - 05/03/10 at 08:32:21 Thanks Raz, I'm going up a local mountain with my bike and laptop to see if I actually get a different, ie higher reading from the ecu to rule out a bad sensor
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Quattroporte YaBB Newbies Offline I love MyECU! Posts: 39	Re: Pressure-Altitude Sensor issue Reply #3 - 05/03/10 at 09:42:57 Ok, so 720 feet up i got a reading of 901mb so at least it's changed from 922 at sea level and working in the correct direction and aprx ratio. I'm wondering if anyone has different pressure sensor defaults to compare? Regards Charles
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Quattroporte YaBB Newbies Offline I love MyECU! Posts: 39	Re: Pressure-Altitude Sensor issue Reply #4 - 05/03/10 at 09:58:48 Here's the image of the sensor... a Motorola <IMG src="http://img.auctiva.com/imgdata/4/6/0/0/5/7/webimg/369845791_o.jpg">
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Quattroporte

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Re: Pressure-Altitude Sensor issue
Reply #5 - 05/03/10 at 13:25:34

After much trial and error, I have established a top value of 4291mV will get me the proper Barometric reading of 1015mB or 29.97 inches of Mercury as confirmed by the Airport ATIS altimeter reading.

Might be useful for someone that cant figure out why other folks maps are not even close to working well if they have the sensor type that I pulled from the 2004 v11s ecu.

Still had to fatten up the midrange but that explains why I had to overhaul the map I started with....

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Re: Pressure-Altitude Sensor issue
Reply #6 - 05/03/10 at 15:47:09

This is from the erratta that you should of received.

3 - The OEM ECU uses 3 different pressure sensors. In your map file you
should change the presssure line with one of the following
MyECU Cfg Pressure=250mV,120mB,4200mV,1060mB
MyECU Cfg Pressure=250mV,120mB,3900mV,1060mB
MyECU Cfg Pressure=250mV,120mB,4750mV,1060mB

If you see 1024mB displayed it is probably invalid. One of the lines
should give you a sensible reading.

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raz

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Guzzi 11OO Sport, My16MkV,
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Re: Pressure-Altitude Sensor issue
Reply #7 - 05/03/10 at 16:19:59

YaBB Administrator wrote on 05/03/10 at 15:47:09:

MyECU Cfg Pressure=250mV,120mB,4200mV,1060mB
MyECU Cfg Pressure=250mV,120mB,3900mV,1060mB
MyECU Cfg Pressure=250mV,120mB,4750mV,1060mB

According to page 5 of http://www.freescale.com/files/sensors/doc/data_sheet/MPX4115A.pdf the first line of the above should be best for yours. But empirical data is even better if you trust the references (but that difference should be really negligble).

Edit: Actually if you use the formula mentioned there, a Vs of 5.0 volts and considering the line seem to better start from 150 mBar, I would use
MyECU Cfg Pressure=200mV,150mB,4295mV,1060mB

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« Last Edit: 05/04/10 at 03:12:28 by raz »

59° North
1100 Sport iniezione elettronica -- the perfect merge of a superbike and a steam train

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Quattroporte YaBB Newbies Offline I love MyECU! Posts: 39	Re: Pressure-Altitude Sensor issue Reply #8 - 05/04/10 at 03:51:12 Thanks RAz, I'll try that line to see where it puts the pressure...
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Quattroporte YaBB Newbies Offline I love MyECU! Posts: 39	Re: Pressure-Altitude Sensor issue Reply #9 - 05/04/10 at 12:54:43 Raz your numbers work well and the mB is quite accurate. Thanks for the suggestion. with only a k&n filter and open pipes, I cannot believe how much mixture I have had to add to the map to get it running well, aprx 15 to 25 percent in some areas... REgards Charles Swanberg
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