FIXED my noisy MAP, TPS, AIT, CLT, and AFR signals for $2.50....
#1
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I installed a $2.50 ebay noise filter to the power supply feeding the MS. I actually bought 3 for 19.50 shipped so I'd have some extras to play with. Anyways, finally installed one after the relay that powers MS. All I can say is every MS on earth should have one of these on the power supply. The pictures below are from my most recent datalog before adding the filter. Same exact MSQ on both datalogs for comparison. Nothing was changed but adding the noise filter.
BEFORE:
![Name: noise1.jpg
Views: 922
Size: 86.9 KB](https://www.miataturbo.net/attachments/megasquirt-18/208046d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noise1.jpg)
![Name: noise2.jpg
Views: 834
Size: 89.9 KB](https://www.miataturbo.net/attachments/megasquirt-18/208047d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noise2.jpg)
![Name: noise3.jpg
Views: 769
Size: 92.0 KB](https://www.miataturbo.net/attachments/megasquirt-18/208048d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noise3.jpg)
![Name: noise4.jpg
Views: 767
Size: 79.8 KB](https://www.miataturbo.net/attachments/megasquirt-18/208049d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noise4.jpg)
AFTER:
![Name: noisegone1.jpg
Views: 788
Size: 83.9 KB](https://www.miataturbo.net/attachments/megasquirt-18/208050d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone1.jpg)
![Name: noisegone2.jpg
Views: 768
Size: 79.3 KB](https://www.miataturbo.net/attachments/megasquirt-18/208051d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone2.jpg)
![Name: noisegone3.jpg
Views: 754
Size: 66.4 KB](https://www.miataturbo.net/attachments/megasquirt-18/208052d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone3.jpg)
![Name: noisegone4.jpg
Views: 767
Size: 74.9 KB](https://www.miataturbo.net/attachments/megasquirt-18/208053d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone4.jpg)
![Name: noisegone5.jpg
Views: 761
Size: 75.0 KB](https://www.miataturbo.net/attachments/megasquirt-18/208054d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone5.jpg)
It's not perfect, but it's a lot better. Before I couldn't ever tune my acceleration enrichments right because the spec of noise I had on my TPS and MAP sensors. If I tuned them right and it picked up any noise it would trigger them, causing the car to flood. So now I should be able to dial in my acceleration enrichments without worrying about noise. Everything in general is just smoother though.
I'll also add that I bet there's still room for improvement. My grounding scheme is pretty poor. All ground wires hook to a 24 point grounding bar, much like the one used in a 200A square D box.
I believe I'm gonna move the LC-1's grounds off of everything else's, as well as the ignition systems grounds. (have a feeling the ignition system's ground is the major source of noise in the first place) I may also add a filter to the LC-1 after redoing my grounds to see if I can further improve that signal.
Also it was it was 49*F today on the "After" datalog pics. Lowest temp it recorded was 48.7*F, highest 51.4.
Datalog from today attached as well. Actually, it failed to attach. Why can't I EVER attach a msq or xls? Is there a trick to this or something? It always fails.
![](https://www.miataturbo.net/images/smilies/beer.gif)
![Friday](https://www.miataturbo.net/images/smilies/friday.gif)
![big grin](https://www.miataturbo.net/images/smilies/biggrin.gif)
![yippee](https://www.miataturbo.net/images/smilies/yippee.gif)
![Biggthumpup](https://www.miataturbo.net/images/smilies/biggthumpup.gif)
I installed a $2.50 ebay noise filter to the power supply feeding the MS. I actually bought 3 for 19.50 shipped so I'd have some extras to play with. Anyways, finally installed one after the relay that powers MS. All I can say is every MS on earth should have one of these on the power supply. The pictures below are from my most recent datalog before adding the filter. Same exact MSQ on both datalogs for comparison. Nothing was changed but adding the noise filter.
BEFORE:
![Name: noise1.jpg
Views: 922
Size: 86.9 KB](https://www.miataturbo.net/attachments/megasquirt-18/208046d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noise1.jpg)
![Name: noise2.jpg
Views: 834
Size: 89.9 KB](https://www.miataturbo.net/attachments/megasquirt-18/208047d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noise2.jpg)
![Name: noise3.jpg
Views: 769
Size: 92.0 KB](https://www.miataturbo.net/attachments/megasquirt-18/208048d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noise3.jpg)
![Name: noise4.jpg
Views: 767
Size: 79.8 KB](https://www.miataturbo.net/attachments/megasquirt-18/208049d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noise4.jpg)
AFTER:
![Name: noisegone1.jpg
Views: 788
Size: 83.9 KB](https://www.miataturbo.net/attachments/megasquirt-18/208050d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone1.jpg)
![Name: noisegone2.jpg
Views: 768
Size: 79.3 KB](https://www.miataturbo.net/attachments/megasquirt-18/208051d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone2.jpg)
![Name: noisegone3.jpg
Views: 754
Size: 66.4 KB](https://www.miataturbo.net/attachments/megasquirt-18/208052d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone3.jpg)
![Name: noisegone4.jpg
Views: 767
Size: 74.9 KB](https://www.miataturbo.net/attachments/megasquirt-18/208053d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone4.jpg)
![Name: noisegone5.jpg
Views: 761
Size: 75.0 KB](https://www.miataturbo.net/attachments/megasquirt-18/208054d1501256473-fixed-my-noisy-map-tps-ait-clt-afr-signals-%242-50-noisegone5.jpg)
It's not perfect, but it's a lot better. Before I couldn't ever tune my acceleration enrichments right because the spec of noise I had on my TPS and MAP sensors. If I tuned them right and it picked up any noise it would trigger them, causing the car to flood. So now I should be able to dial in my acceleration enrichments without worrying about noise. Everything in general is just smoother though.
I'll also add that I bet there's still room for improvement. My grounding scheme is pretty poor. All ground wires hook to a 24 point grounding bar, much like the one used in a 200A square D box.
![](https://www.miataturbo.net/images/smilies/bowrofl.gif)
Also it was it was 49*F today on the "After" datalog pics. Lowest temp it recorded was 48.7*F, highest 51.4.
![Biggthumpup](https://www.miataturbo.net/images/smilies/biggthumpup.gif)
#3
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$2.90 plus 5.90 shipping = 8.80 shipped FTW.
Noise Filter 10 AMP Car Audio 12V Stereo RCA Isolator - eBay (item 270265692541 end time Mar-12-09 19:41:27 PDT)
Noise Filter 10 AMP Car Audio 12V Stereo RCA Isolator - eBay (item 270265692541 end time Mar-12-09 19:41:27 PDT)
#5
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My car has also had an untraceable "hickup" before. Like it would randomly "go off" for 0.1 seconds and then come back on. I would only notice it a very light load or idle, but it usually happened once ever 10-20 minutes of driving. So far it hasn't done it, but time will tell if the noise filter fixed this as well.
#7
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They used to sell them, but they stopped selling useful things several years ago. Now they sell cell phones, TV's, expensive shitty electronics, and expensive shitty cables to wire them up.
#13
2 Props,3 Dildos,& 1 Cat
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it's probably just a huge coil.
it's essentially a crossover component--low pass, but for very low frequencies. ie almost zero hertz (DC).
or it could be an RC circuit with a big cap and a small resistor.
it's essentially a crossover component--low pass, but for very low frequencies. ie almost zero hertz (DC).
or it could be an RC circuit with a big cap and a small resistor.
#20
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Sooo... I fixed some things and now it's worse!! Woo hoo!!.... Moved the ignition systems ground off of everything else's and now I get more noise on my wideband than before.
But now, the rest of the story. One of the grounds for the LC-1 was wasn't grounded. I'm pretty sure it has been that way, unless I pulled it loose right before I noticed, but I don't think that's the case. Weird, but it's noisier now. Gonna try adding a filter to the LC-1's power and see if that helps. Or try moving the LC-1's grounds around.
But now, the rest of the story. One of the grounds for the LC-1 was wasn't grounded. I'm pretty sure it has been that way, unless I pulled it loose right before I noticed, but I don't think that's the case. Weird, but it's noisier now. Gonna try adding a filter to the LC-1's power and see if that helps. Or try moving the LC-1's grounds around.