ric

Hello all!

I want to fit the MRT fuel cut lifter on a MY00.

I need to know which cable is the MAP sensor on the ECU.

Also, where should I take 12+ and mass from?

Are the MY99 and MY00 ECUs the same?

Thanks for any help
ric

john banks

MY99/00 are the same. See the Link manual for a wiring diagram. http://www.mrtrally.com.au/performance/docs/WRX-V5.pdf it is listed under Pressure sensor. Don't know about other model years. Most FCDs usually use a 5V supply which you can take from the throttle position sensor supply, but if you need 12V then any ignition positive 12V supply would be OK? There are lots at the ECU if you trace the power circuits in the Link manual. Only connect to the 5V ECU supply if that is what the circuit is designed for - I don't know the maximum power rating and have not tested this 5V supply yet!

[Edited by john banks - 3/15/2002 3:46:45 PM]

ric

Thanks a lot John!

seya
ric

Miki

ric,

did you actually get a Fuel Cut Lifter from MRT? I got mine last week, and it's now a Boost Cut Defender, i.e. no more fuel cut whatsoever...

MRT didn't inform me about this change at all, I noticed it when the package arrived! What happened after that is a long story, but I got some overall compensation for a couple of screw-ups from their part and now I'm once again pleased with MRT's way of handling things, so enough said about that.
Back to the wiring, does anyone know which wire I should use on a MY95 for the FCD, I have the diagram in front of me and it has indication of boost pressure on several pins.

This is what it says:

A03 boost pressure sensor +5V (Pin C of Map sensor)
A04 boost MAP pressure signal (Pin B of sensor)
A21 sensors ?V atmo air clt (Pin A of map sensor)
B08 atmos 2 sig alternative Map input (Mapi Pin B)

which one is it ?????

* Miki *

Chris.Palmer

On a Pre My 97 - I think you need connector B43, the bottom connector is B43.

Pin 4 is MAP signal
Pin 3 is MAP 5v supply.
Pin21 is MAP GND.

There's a diagram on my website if that helps.

PS - I believe MAP on pre MY97 misreads above 1.05 Bar thats why fuel cut is set here.

[Edited by Chris.Palmer - 3/20/2002 11:12:08 AM]

Miki

>On a Pre My 97 - I think you need connector B43

Chris, thanks for your diagram pics, the connector names are missing from the wiring diagram I have, otherwise I think they're the same. The naming of the pins is a bit different, I think it's more clear on your diagram, but the colors of the wires are mentioned on mine. The connector which is called "B43" on your diagram is called "A" on mine... but the pins are the same, i.e. 3 and 4, so I should then use pin 4 , right ???

>PS - I believe MAP on pre MY97 misreads above 1.05 Bar thats why >fuel cut is set here.

Does this mean I should upgrade the MAP sensor? To what kind of sensor, make, model, part#....

* Miki *

[Edited by Miki - 3/20/2002 1:36:59 PM]

ric

Hello John, the MRT wiring diagramm does not really fit my MY00 ECU?!?!

B136 pin 7 for pressure sensor is nothing?!

thanks
ric

Chris.Palmer

Miki,

Pin 4 - to adjust the defend.
Pin 3 - for a 5v supply (if you need one)

A good question - unfortunately I do not have a definitive answer.

I believe the early STIs ran higher boost as standard so maybe their MAP sensors are better. Having said that I think they had Closed Decks Blocks, different turbos, intercoolers - piping - the works.

There may even be other limitations on the early UK MYs that make it unsafe to raise the boost.

I would like to know myself!

Maybe I should start another thread & see if someone knows for certain.

Chris

[Edited by Chris.Palmer - 3/20/2002 2:20:24 PM]

john banks

I am puzzled Ric - B136 pin 7 is definitely the MAP sensor on mine! Gives about 2.29V with engine off ignition on depending on atmos pres on the day.

ric

THANKS FOR YOUR ANSWER JOHN,

THE PROBLEM IS, THAT THE DIAGRAMM OF EVERYTHING WAS FOR THE RHD CAR, BUT THE LHD CARS ARE JUST EVERYTHING TURNED!

I FINALLY MANAGED TO FIT THE FCD AND A BLEED VALVE. SET IT TO 1.3BAR PEAK DROPPING TO 1BAR@6000RPM (CAR HAS DOWNPIPE).

THANKS A LOT JOHN AND ALL OTHER PERSONS WHO HELPED ME!
RIC

[Edited by ric - 3/20/2002 9:12:03 PM]

Miki

ric,

so did you get a Fuel Cut Lifter or a Boost Cut Defender from MRT?

* Miki *

BugEyed

Miki

Are they not the same thing? In both cases the unit is interupting the signal from the MAP sensor and sending through a revised version to the ECU. This should allow the car to run a higher level of boost without the ECU cutting the fuel or going to a less aggressive ignition/fueling map.

Does anybody have details of what this unit is capable of;

• does it just limit the MAP signal to a maximum amount like the HKS, or does it just restrict it for a limited period like the John Banks DIY version?
• is it limited to just one pressure point, or can it be set to different values for different RPM?

Sorry for the questions, but I can find anything on the MRT website.

Thanks

Duncan

john banks

I call this a lifter:


And this a defender (red line):


But that is just my terminology.

[Edited by john banks - 3/21/2002 8:32:12 AM]

ric

I think it is a lifter, as it starts to react when you want it to react and the point is adjustable with a screw and you can see a light illuminating.

It is very easy to set up and works fine.

ric

Miki

According to the installation instructions that came with the gadget there is no more fuel cut active after the installation, so in my opinion it removes the cut, i.e. it's not a "Lifter".
When I asked MRT about this they said that their supplier changed to this product, but that it does "exactly the same job". I have to disagree on that, unless the previous also removed the fuel cut although it was called a Lifter, of course...

On my box it says Boost Cut Defender, and it doesn't even look like the one on MRT website. I asked them to update their website to avoid further misunderstandings, doesn't seem to have happened yet though.

One more question ric,
did you stop the car to adjust the **** or did you adjust it under full boost, I'm having slight probs understanding their instructions...

* Miki *

ric

Miki,

Seeing John's graphics now I think it is a FUELCUTDEFENDER, that completely removes the cut out point.

I adjusted the thing when driving, but not under boost. Its an easy job and possible to adjust when driving, but be careful, driving, watching boost gauge and fiddling with the FCD thingy might be dangerous. We were 3 people. One checked boost, I drove and the other one adjusted the FCD. Works fine now!

With the screw your are adjusting the limit value. Say you adjust to 4.5V. Then until 4.5V nothing happens, but when the MAP sensor gives readings over 4.5V the FCD limits the signal seen by the ECU to 4.5V. As soon as it is defending (limiting the Volt value of the MAP) a signal lamp illuminates. Set the FCD that the signal lamp just illuminates at around 1.15bar.

I think it is a good thing this MRT FCD, it works and it is adjustable, so you can use it on different cars.

Be careful when soldering into the ECU wiring, I worked the whole afternoon to make sure I sold the right cables! LHD and RHD cars are NOT the same!!! (everything is in a MIRROR methinks..)

seya
ric

PS John, thanks again for providing all this info to us and helping people around the world (Finland, Switzerland etc.) to make their Scoobs go better!

Miki

Thanks for the advice ric, I plan on fiddling with this gadget during the weekend, hope everything turns out well... ;P

Considering what you said about the mirror thing, I still have to study the wires a bit. The diagrams I've got are probably both from England, but at least the guy at the local workshop managed to install Unichip on my car using the other one... maybe it isn't mirrored on older models, go figure...

* Miki *