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Discussion Starter #1 (Edited)
i wired in a 50psi map sensor into the aem v2 but it seems like it is not reading correctly. at idle and vacuum around -15psi the map sensor is reading at -0.2

it is not reading an "error" but it seems like it's off. i picked the aem 3.5 bar map sensor in the wizard. i believe i have it wired in correctly as well...

41b, 62b and 65b (ground) is what it is wired into..

i read somewhere that one of the wire (green?- map signal wire needs to have the stock harness wire cut and that red wire, wired in to the ecu pin and not just tapped in (the other 2 are ok to be tapped)?

anyway thanks for any help!!
 

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Discussion Starter #2
I unscrewed the map sensor and blew on it giving some pressure, and the car reacted to it for sure, but it still only went up to 0 psi.. so I'm not sure exactly what's going on here if it's a bad map sensor or is it some adjustment/calibration change?
 

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Discussion Starter #4
It is tapped in. Do I have to cut the wires from the ecu off & wire it in and leve the other end open?
It is a brass sensor that says 50 psi.. Aem guy just said he doesn't recommend that one.. Not sure if that is the only culprit
 

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Tapped in is fine. However I would not recommend brass for a MAP sensor. Who is the manufacturer of the brass sensor? Do you have a part number? When you say it says 50psi does it say 50psig, 50psia or just 50psi? Also where is the sensor located? Where are you plumbing the sensor in? Before throttle body or after?
 

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If its in the manifold, and has no AEM sticker on the sensor, the reason your map sensor isn't reading correctly is because you need to find the correct voltage chart for the map sensor. This is why part number has popped up a few times.

You have three ways to ensure the sensor works. You put a pressure source on it (air compressor), you take a multimeter to make sure your ground is good. If you're on a USDM car, you should have cut the connector off the turbo pressure sensor on the manifold off and used the three wires from that. Only other thing is to swap sensors.

This issue ties directly into your fuel at idle issue. Fix this, and everything should be fine. Right now your car is injecting fuel equivalent to 0 psi in the manifold when you are really at -7.
 

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Discussion Starter #7
Pretty awesome replies.. Tyvm guys I'll check and get back

Sensor is before throttle body.. On the if pipe down by radiator.
Should it be IN the manifold??

Brass fitting not sure brand or model #. Just says 50 psi
 

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Pretty awesome replies.. Tyvm guys I'll check and get back

Sensor is before throttle body.. On the if pipe down by radiator.
Should it be IN the manifold??

Brass fitting not sure brand or model #. Just says 50 psi
Yeah, that could be your problem. Unless you purchased it as a 3.5 bar AEM Map sensor from a vendor, the brass sensors AEM sells dont show up with stickers or anything on them. The stainless steel sensors are the ones that have part number stickers on them. If you put the car in ignition, and it does not show 0 psi, +- .1, then its a map sensor issue. Everything, breakpoints, tables, relies on the map sensor reading.

The sensor can be tapped in the manifold, or receive a vacuum source from the manifold to the sensor.
 

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Discussion Starter #10
Gotcha so I should put it in the manifold. Any place there is? So it's after the throttle body

I should just get the stainless Aem 3.5 map sensor then
 

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If thats what you have selected in the AEM setup wizard, then I would begin to look at your connections.

CAR HARNESS_____________MAP SENSOR
Blue/Red_________________Red____________5 Volts
Brown/Black*_______________Black__________Ground
Black/Yellow_______________Green__________Output
 

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Discussion Starter #13
Ty.. I'll wait for the Aem map sensor and make sure I wire it up that way.. Thx for the info on wires..
Where do people place their map sensor on the intake manifold?
 

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The sensor is not defective however you have it installed in the wrong location. It needs to pull a vacuum/boost source after the throttle body not before. However I would not use a brass sensor as your map sensor.
 

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Discussion Starter #17
Gotcha maybe I should replace it anyway even if it works.

But how/where do you make changes to the map sensor volts/calibration? Is there a graph for it? I know in the sensor selection there's a few map sensor settings/info
 

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Discussion Starter #19
if it's not in the selected wizard? how can I input these custom volts/load to calibrate it manually?
 

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It is located under the sensors tab however MAP sensors are linear so you would need a min value, max value, load offset and scalar. If you are trying to calibrate that brass sensor for your map sensor select the 30-2130-50 sensor as it is the same. However there is nothing wrong with your sensor you have it installed in the wrong place.

Also not trying to be mean or anything, but with the questions you are asking here and other forums(since I have seen the same questions) I would suggest you take your car to a local tuner near you. The questions you are asking are basic installation and tuning questions.
 
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