subaru 96 v2.28 new map sensor fitting

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2ltrrabbit
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subaru 96 v2.28 new map sensor fitting

Post by 2ltrrabbit » Sun Jan 05, 2014 2:12 pm

Hi,
I decided to start a new topic on this problem i have.
situation as is;
Gems ecu in and working on standard sensors, all good.
However I'm trying to install the new 3 bar map sensor supplied by you guys but I'm getting a few problems.
Firstly, once i have installed the sensor and wired it in as to the gems manual it works fine. However as i add pressure to the sensor [via a pump to achieve the max map raw value] the sensor runs out of range with a reading of 250 raw and only 2 bar of pressure. Is this because its reading the atmosphere at 1 bar hence the lost 1 bar range? which will be used under vacuum?
Secondly, my water temp is now out of range and the fans kick in. temp is reading 100 degrees c. After looking at pinout diagrams and comparing them to the gems manual i found what looks to be the problem. The stock old sensor only has two wires new one has three. The wires b and c from new sensor are wired correctly however wire a is being shown to be wired into the water temp computer. Which is causing the upset with the reading.
Thirdly, could you explain to me what the map mbar m and map mbar c are used for.
Kind regards
steve

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RickS
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Re: subaru 96 v2.28 new map sensor fitting

Post by RickS » Mon Jan 06, 2014 10:03 am

Hi Steve,
How have you calibrated the sensor..? Have you set the 'MAP Min' and 'MAP Max' from the 'MAP raw' parameter..?

The 'MAP mBar M' is a multiplier and 'MAP Mbar C' is an offset used to scale the MAP parameter. It is used thus....
Air Pressure = ('MAP raw' x 'MAP Mbar m') + MAP Mbar C.

I will look into the coolant sensor issue (please send me details of the sensor...?). Is your option 'Coolant Default' set to 100, as it sounds as if the default is being used instead. Again, how has this sensor been calibrated as I have not heard of a 3-wire temperature sensor being used on one of our Subaru ECUs ..?

Best regards,
RickS
PS. If you'd prefer, send a copy of the .CAL to tech (dot) support (at) gems.co.uk

2ltrrabbit
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Re: subaru 96 v2.28 new map sensor fitting

Post by 2ltrrabbit » Mon Jan 06, 2014 12:42 pm

Hi Rick,
I think you may have misread my topic slightly.
The problem is the map sensor you have supplied. If I wire it into the loom as what the gems manual says it interferes with the cars water temp gauge. That's why ecu is going into out of limit reading 100 degrees.
Since writing I have removed map sensor to be able to run car. The problem is wire A as in gems manual it's shows it wired into car temp sensor.

To set map I input the map min by car switched off ( or should it be at idle?) and map max I pressurised the sensor. It's a 3 bar sensor but it only reached 2 bar.

So if I put new map raw settings in do I need to change the map Mbar m and map mbar c values?

Regards
Steve

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RickS
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Re: subaru 96 v2.28 new map sensor fitting

Post by RickS » Mon Jan 06, 2014 1:05 pm

Probably mis-understood...
OK, which pins have you wired the MAP sensor to...? I reckon 'A' goes to A21, 'B' goes to A04 and 'C' goes to A03.
BR, RickS

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Re: subaru 96 v2.28 new map sensor fitting

Post by 2ltrrabbit » Mon Jan 06, 2014 1:45 pm

Sorry my grammar i expect
Yeah that's what i have here too, however if you look at a pinout for this ecu A21 is a water temp signal for ecu. the standard map sensor only has two wires which are a3 and a4.
cheers

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RickS
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Re: subaru 96 v2.28 new map sensor fitting

Post by RickS » Mon Jan 06, 2014 2:03 pm

I have A07 as Coolant Water temp signal.

I will prepare a pinout for a Subaru 96 and post it here.
BR, Rick.....

PS.. Attachment added. Please update me if there are any inconsistancies
Attachments
SUBARU96 ECU connection list.docx
Subaru96 Pinout
(16.1KiB)Downloaded 904 times
Last edited by RickS on Mon Jan 06, 2014 2:20 pm, edited 1 time in total.
Reason: Adding attachment

2ltrrabbit
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Re: subaru 96 v2.28 new map sensor fitting

Post by 2ltrrabbit » Mon Jan 06, 2014 2:05 pm

ao7 and a21 are both water temps on my pinout diagram
jap car not uk

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RickS
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Re: subaru 96 v2.28 new map sensor fitting

Post by RickS » Mon Jan 06, 2014 2:37 pm

A21 is a 'ground' pin so can be used as a ground for MAP (as the earlier attached pinout) and Coolant Temp if required.
BR, RickS

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Re: subaru 96 v2.28 new map sensor fitting

Post by 2ltrrabbit » Mon Jan 06, 2014 2:48 pm

ok, I've disconnected Ao21 and water temp has shot up to 100 default.
Do i just splice map sensor into the loom?
At the moment i have cut and joined new sensors to loom and left old wires sensors unconnected?
Is this right?

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RickS
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Re: subaru 96 v2.28 new map sensor fitting

Post by RickS » Mon Jan 06, 2014 3:29 pm

As long as you are only using one MAP and one coolant sensor you can either remove and replace the old wiring or splice into the loom.

The pins that I suggest that you use are i) MAP..... A03 = +5v, A04 = MAP signal and A21 = 0v and ii) for the Coolant sensor A07 = signal and suitable gound for which A21/A22 will do.

Please give me details of the two wire MAP sensor that you have been using. I would like to inveatigate this further.
BR, RickS

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Re: subaru 96 v2.28 new map sensor fitting

Post by 2ltrrabbit » Mon Jan 06, 2014 4:51 pm

I think we are getting a bit lost here.
I'm only fitting the upgrade 3 map sensor supplied by gems. The water temp is all standard.
The problem I'm getting is when I wire in wire A of map sensor to ecu pin a21 it knocks out my temp sensor to ecu.
If a21 is a sensor earth can I just join the map sensor to it?? And with wire c and b I will cut and join leaving out the old sensors wires.

Also when I applied pressure to the sensor to achieve map max are it only went to 2 bar with a raw value of 250.
When I set map raw min is this the value when the car is at idle or at atmosphere pressure ie no vacuum.
Regards Steve

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RickS
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Re: subaru 96 v2.28 new map sensor fitting

Post by RickS » Tue Jan 07, 2014 9:37 am

No, I understand the picture. The anomaly seems to be the 'extra' wire that your new MAP sensor has. All of the sensors that we sell are three wire either (1.2 bar or 3 bar). You mentioned earlier that your MAP sensor had 2 wires and I asked for details of the sensor so that I could check for differences.

Please give me the job number issued when you bought the sensor and I will check the stock that was sent to you to see if you have been sent a malfunctioning one in error.

You would calibrate the MAP sensor with the ignition off. To check that the sensor is working properly, firstly you should check if the sensor produces a signal. This can be done independently from the engine vacuum, using a vacuum pump. Next you should test whether the sensor is getting power with a multimeter. Then go on to checking the ground point of the circuit. Based on the results of these three simple tests you can asset whether you need to change or replace the MAP sensor.

I have attached a list of tables showing MAP voltages which I hope will be of use.

Best regards, RickS
Attachments
MAP voltages.odt
MAP sensor voltages
(7.46KiB)Downloaded 844 times

2ltrrabbit
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Re: subaru 96 v2.28 new map sensor fitting

Post by 2ltrrabbit » Tue Jan 07, 2014 11:34 am

Morning Rick,
well I've been out in the workshop with the car so have some results.
as requested the part number for the standard map sensor
denso
222012aa020
079800-1720
and also the part number for the 3 bar map sensor supplied by gems
1222386
lot1951

I have been playing with the map raw settings on the standard map (denso) and found its best to set map min raw with car on idle. gives a much better throttle response.
Do i now need to change any of the map mbar m/c settings?
kind Regards
Steve

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RickS
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Re: subaru 96 v2.28 new map sensor fitting

Post by RickS » Tue Jan 07, 2014 12:56 pm

I will try and find some information regarding the MAP mBar c/m option values and post them here.

So I can get a feel to the your particular requirements, what boost are you hoping to obtain with your current setup.?
Best regards, RickS

Note. Base 2.28 workmap set for approx 2.5Bar attached. Please use as reference only.
Attachments
WORKMAP.SUBARU96.V2.28.cal
Base V2.28 3Bar Boost Map
(9.92KiB)Downloaded 843 times
Last edited by RickS on Tue Jan 07, 2014 4:44 pm, edited 1 time in total.
Reason: Adding base calibration....

2ltrrabbit
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Re: subaru 96 v2.28 new map sensor fitting

Post by 2ltrrabbit » Tue Jan 07, 2014 5:08 pm

With this engine I would be looking at 1.4 bar max.
I'm guessing that the map mbar m/c settings are there to scale the map sensor so the parameter map bar reads a correct value in bar. Ofwhich the target boost map uses?
At the moment I'm using the waste gate duty map to control boost.
So any info on how to set up the mbarm/c settings would be awesome.
Kind regards
Steve

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