random "hickup"
#1
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i really dont know what to think about this. my car has a completly random hickup, enough to see it come up on the tach, but i havent been able to notice anything in a datalog. it is completly random, will happen partial throttle and also at WOT. any ideas on what what to look for? i will go over all of the ground, but besides that, im clueless.
also, i have the solid MMR motor mounts, ever sence i put them in, the guages shake a ton, the tach is by far the worse, speedo is the least. is there anyfix for this?
also, i have the solid MMR motor mounts, ever sence i put them in, the guages shake a ton, the tach is by far the worse, speedo is the least. is there anyfix for this?
#2
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So the MS isn't spontaneously resetting then, correct? (Shows up as a horizontal red line in the log)
Install softer motor mounts.
also, i have the solid MMR motor mounts, ever sence i put them in, the guages shake a ton, the tach is by far the worse, speedo is the least. is there anyfix for this?
#4
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MSPNP or DIY MS?
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Jerry a.k.a. 'FoundSoul'
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A few other cars....
#6
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Although it seemed to affect primarily HR users, there was a fault recently discovered in the CMP (secondary) CAS input which caused noise on the input and resulted in exactly this problem.
The solution was to lay a .1uf capacitor between pins 11 of the CPU socket and ground. Read all 'bout it: http://www.msextra.com/viewtopic.php?t=26727
Might be worth a shot.
The solution was to lay a .1uf capacitor between pins 11 of the CPU socket and ground. Read all 'bout it: http://www.msextra.com/viewtopic.php?t=26727
Might be worth a shot.
#7
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It's very likely noise on the 2nd trigger causing an occasional misfire. Check out this thread for more info: https://www.miataturbo.net/forum/sho...t=14871&page=2
Or this thread for all the technical details- http://www.msextra.com/viewtopic.php?t=26727&highlight=
But if this is it, to fix it, put a .1uf capacitor between JS8 and GND. That's it!
Or this thread for all the technical details- http://www.msextra.com/viewtopic.php?t=26727&highlight=
But if this is it, to fix it, put a .1uf capacitor between JS8 and GND. That's it!
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Jerry a.k.a. 'FoundSoul'
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'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
#8
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heh... I took to long to dig up those links ![wink](https://www.miataturbo.net/images/smilies/wink.gif)
BTW-- it helps non-HR users too... the 90-95 cars aren't as bad about this, the 96-97 cars had a noisier signal, but this solves it across the board...
![wink](https://www.miataturbo.net/images/smilies/wink.gif)
BTW-- it helps non-HR users too... the 90-95 cars aren't as bad about this, the 96-97 cars had a noisier signal, but this solves it across the board...
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Jerry a.k.a. 'FoundSoul'
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'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
#9
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I can't say whether this mod solved any particular problem for me as I did it prior to installing my MS.
Last edited by Joe Perez; 01-30-2008 at 09:48 PM.
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Any reason why adding a .1uf cap where you describe would harm an AEM EMS? I don't know what adding a cap to ground does electronically, but could the AEM EMS have some sort of wiring that would go ::FIZZZ:: if a cap was wired there?
My AEM does this too. Tach drops for a split second, ~0.1sec spike shows up on the RPM datalog. Mostly fixed when I went to the 1.8 but still there a little. If 12cents CAN'T HURT i'll try it. Any ideas?
My AEM does this too. Tach drops for a split second, ~0.1sec spike shows up on the RPM datalog. Mostly fixed when I went to the 1.8 but still there a little. If 12cents CAN'T HURT i'll try it. Any ideas?
#19
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The circuit is more than just a cap though... it's just in our case, the resistor that was needed was already there.....
Here's the full circuit. Ignore the one on the left as it's just an example of what didn't work. The circuit on the right does work... You'd want to make sure there is a resistor in between the CAS 2nd trigger input and the processor, and right in between those two put the .1uf cap to ground.
![](http://www.diyautotune.com/images/forum_pics/msextra_4-2miss/fix_schem.gif)
Note you shouldn't need to worry with the pullup to 5v as that should be taken care of already...
Here's the full circuit. Ignore the one on the left as it's just an example of what didn't work. The circuit on the right does work... You'd want to make sure there is a resistor in between the CAS 2nd trigger input and the processor, and right in between those two put the .1uf cap to ground.
![](http://www.diyautotune.com/images/forum_pics/msextra_4-2miss/fix_schem.gif)
Note you shouldn't need to worry with the pullup to 5v as that should be taken care of already...
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Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....