twitching oil pressure gauge.

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christiansend83
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twitching oil pressure gauge.

Post by christiansend83 »

I've got an MS3pro EVO, and am trying to wire up a map sensor to be use as an oil pressure gauge.
Under the Generic sensor input section. I set it to Analog In 3, set the voltage values, and burn it. After putting a gauge on the dash board I notice that the gauge will twitch between 0.5 - 23.7 I've tried wiring it to a different source and get the same results. Even with no wire in the ecu connector, I get the same results. Seems like its something inside the MS3? Any idea's or suggestions why this might be happening, or what I can do to smooth things out. Thanks in Advance!

Here is a small video of the problem. https://youtu.be/7uDIhMr6AJI
Raymond_B
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Re: twitching oil pressure gauge.

Post by Raymond_B »

How do you have it wired?

Also let's see the MSQ

:msq:
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racingmini_mtl
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Re: twitching oil pressure gauge.

Post by racingmini_mtl »

I bet you have the knock sensor debug data enabled. You cannot use that and the generic sensor at the same time since they use the same variables.

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christiansend83
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Re: twitching oil pressure gauge.

Post by christiansend83 »

All knock control is currently disabled.

As for how its wired, Its a 5v, 100 psi transducer. 5v's comes from the 5v ref. and ground is signal ground. signal goes to the analog in 3.

I will post the MSQ as soon as I am able. ( next day or so )
Paul_VR6
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Re: twitching oil pressure gauge.

Post by Paul_VR6 »

Can you post the sensor? I have seen that behavior from some of the brass bodied sensors.
-Paul
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jacky4566
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Re: twitching oil pressure gauge.

Post by jacky4566 »

Have you tried bumping up the smoothing ratio?

Also you could put a small 10uF cap on the line to help smooth it physically.

Do you see the same voltage fluctuation with a multimeter/scope?
Raymond_B
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Re: twitching oil pressure gauge.

Post by Raymond_B »

Paul_VR6 wrote:Can you post the sensor? I have seen that behavior from some of the brass bodied sensors.
AEMs or? I ask because I just picked up 3 for fuel, oil, and MAP.
1995 Ford Lightning. Dart based 427 Windsor, Novi 2000, full sequential, E-85, etc. MS3X/v3.57
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christiansend83
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Re: twitching oil pressure gauge.

Post by christiansend83 »

This is the sensor I picked up. http://www.ebay.com/itm/Pressure-transd ... GA&vxp=mtr
Paul_VR6 wrote:Can you post the sensor? I have seen that behavior from some of the brass bodied sensors.
I have not tried bumping up the smoothing ratio. When I look at the signal output from the sensor, the voltage remains constant. Which makes me think the problem lies inside the MS3
jacky4566 wrote:Have you tried bumping up the smoothing ratio?

Also you could put a small 10uF cap on the line to help smooth it physically.

Do you see the same voltage fluctuation with a multimeter/scope?
And... I've attached the MSQ
Matt Cramer
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Re: twitching oil pressure gauge.

Post by Matt Cramer »

The MSQ has the source set to analog in 1 instead of analog in 3. If Analog In 1 is not connected, you're reading random static for your oil pressure.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
christiansend83
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Re: twitching oil pressure gauge.

Post by christiansend83 »

Matt Cramer wrote:The MSQ has the source set to analog in 1 instead of analog in 3. If Analog In 1 is not connected, you're reading random static for your oil pressure.
That is true. Although this is because in my attempt to fix the problem, I have tried switching the pin around to see if I got the same result each time. which I do.
Paul_VR6
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Re: twitching oil pressure gauge.

Post by Paul_VR6 »

What happens if you unplug the sensor and jump signal to ground? Signal to 5v?
-Paul
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christiansend83
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Re: twitching oil pressure gauge.

Post by christiansend83 »

Paul_VR6 wrote:What happens if you unplug the sensor and jump signal to ground? Signal to 5v?
I will try this, and share my results. I do know that with the engine running, it will display oil pressure, but the needle still twitches all over the place. I have another oil pressure gauge in the dash board and can verify that the oil pressure is in fact not jumping all over the place.
prof315
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Re: twitching oil pressure gauge.

Post by prof315 »

The cheap stainless pressure transducers found on E-bay and Amazon are "Hecho en China" (Made in China) and have a roughly 30% initial fail rate. Get another sensor.
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christiansend83
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Re: twitching oil pressure gauge.

Post by christiansend83 »

prof315 wrote:The cheap stainless pressure transducers found on E-bay and Amazon are "Hecho en China" (Made in China) and have a roughly 30% initial fail rate. Get another sensor.
I agree that they are junk, and there are much better sensor choices out there. But here are my results from today's testing that make believe that the problem is not in the sensor.

I unplugged the sensor and jumped a wire from the 5v ref to the signal wire. Here is what the result was...

https://www.youtube.com/watch?v=xPrUzYkGfhI

Also, I checked the voltage on the signal wire with everything plugged in. You can see the voltage on the multimeter remaining steady, and see the dashboard gauge on the lap top going nuts.

https://www.youtube.com/watch?v=14LLcL2Uy8k

Even if I remove the pin in the MS3 plug entirely, The gauge will still go nuts like that. So I would think the problem is inside of the MS3 box.
prof315
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Re: twitching oil pressure gauge.

Post by prof315 »

christiansend83 wrote:
prof315 wrote:The cheap stainless pressure transducers found on E-bay and Amazon are "Hecho en China" (Made in China) and have a roughly 30% initial fail rate. Get another sensor.
I agree that they are junk, and there are much better sensor choices out there. But here are my results from today's testing that make believe that the problem is not in the sensor.

I unplugged the sensor and jumped a wire from the 5v ref to the signal wire. Here is what the result was...

https://www.youtube.com/watch?v=xPrUzYkGfhI

Also, I checked the voltage on the signal wire with everything plugged in. You can see the voltage on the multimeter remaining steady, and see the dashboard gauge on the lap top going nuts.

https://www.youtube.com/watch?v=14LLcL2Uy8k


Even if I remove the pin in the MS3 plug entirely, The gauge will still go nuts like that. So I would think the problem is inside of the MS3 box.
How do you have the sensor grounded? If you are not using the signal ground it won't work right and you'll get the funkiness like your test
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christiansend83
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Re: twitching oil pressure gauge.

Post by christiansend83 »

prof315 wrote:How do you have the sensor grounded? If you are not using the signal ground it won't work right and you'll get the funkiness like your test
I have it grounded through "signal ground"
whttalon95
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Re: twitching oil pressure gauge.

Post by whttalon95 »

Sorry to bump an old thread but I’m seeing similar issues. Did you find a solution to this twitching on your generic inputs?
christiansend83
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Re: twitching oil pressure gauge.

Post by christiansend83 »

I did figure it out. I ended up using generic sensor input 9-11, working well so far. It really doesn’t make much sense but it started working when I choose one of the lower 9 inputs.
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Re: twitching oil pressure gauge.

Post by jsmcortina »

You have probably enabled "Debug" on the knock sensor system - READ THE TOOLTIP !

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christiansend83
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Re: twitching oil pressure gauge.

Post by christiansend83 »

jsmcortina wrote:You have probably enabled "Debug" on the knock sensor system - READ THE TOOLTIP !

James
I somewhat recall someone mentioning this earlier in this thread and I checked it out. I will look again when I get home from work, but I believe it was not enabled. I'll get back and confirm.
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