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ms3x vr circuit adjustment screw up

Old Nov 14, 2012 | 01:48 AM
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Default ms3x vr circuit adjustment screw up

followed the westfieldmx5 ms3x guide before it was updated

EXCEPT instead of being smart and installing R52 and R56 with the adjustment screws up, I apparently decided to ignore the silkscreen picture on the board and soldered them with the screws down

I couldn't figure out why adjusting these resistors couldn't get me into the 2.5v-3.0v range on R54 while turning R56

I'm also failing to do the same on the ms3x board while measuring R17 while turning R11

Did I break it by initially soldering the variable resistors wrong and jimstimming it?

Am I just being even more noob by measuring the wrong place?

I'm also hoping this is the cause of me not getting a trigger signal in the diagnostic composite log and thus not being able to start the car (have fuel, no spark)
Old Nov 14, 2012 | 08:13 AM
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did you flip the pot resistors back around?
Old Nov 14, 2012 | 02:06 PM
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yeah, switched them back around after I posted. I can get the mainboard pot to adjust to 2.75v

the ms3x one will adjust to 2.56v now, but that's the highest I can get it (was hoping for the same as on the mainboard)

haven't tested it in the car yet to see if it'll start up

question, when testing the voltage, I'm supposed to use any ground? or the nearest ground? not sure if there's a preferred ground to use when testing with the voltmeter
Old Nov 14, 2012 | 02:18 PM
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just setup the ms3x ones exactly as written in the docs.

I've never had to adjust them other than exactly as documented (both mainboard and expander), always synced, no complaints, so never tested voltage.
Old Nov 14, 2012 | 02:54 PM
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I had to adjust mine by measuring the voltage. MS3 was reading crank signal, but no Cam signal.
Just counting the turns did NOT work for me and I was off by 0.5V on the Cam signal and by 0.3V on the Crank signal (if I remember the voltages right). There is of course the chance that I didn't count right.
Old Nov 14, 2012 | 03:01 PM
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You should se how many times I do it. I miss count at least 7 times.
Old Nov 15, 2012 | 06:34 PM
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AND...... car is running thanks guys. Using a voltmeter helped after fixing the pots. Now to retune idle. Going from DIYPNP to ms3x is so much more complicated, yet the possibilities are endless
Old Nov 15, 2012 | 06:56 PM
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Idle tuning is easier.
Old Nov 15, 2012 | 07:13 PM
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I'm saying more complicated as in more things to adjust compared to pid, but definitely easier to get perfect, not to mention things make more sense in ms3
Old Nov 16, 2012 | 02:11 AM
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since I've already got a thread up, might as well ask. in the ignition settings for the "ignition input capture" for the ms3, why is it rising edge? whereas in my diypnp, ignition setting are falling edge?
Old Nov 16, 2012 | 02:24 AM
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Originally Posted by bmxfuel007
in the ignition settings for the "ignition input capture" for the ms3, why is it rising edge? whereas in my diypnp, ignition setting are falling edge?
It has to do with the physical circuitry being used to receive and decode the signals from the sensor. In one system, the signals coming from the sensors are electrically inverted during the receive stage, and thus fed to the CPU "backwards". In the other, the signal retains its "correct" polarity throughout the receive stage, and is fed to the CPU in the same polarity as it is received.

This is simply the result of a design choice in the DIYPnP board as opposed to the MS3/X boards. Neither one is right or wrong in an absolute sense- choices of this nature are fairly arbitrary, and the result of the whim of the designer.
Old Nov 16, 2012 | 02:25 AM
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love you guys. thanks for the info
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