Turbosmart - FCD - 1JZ Map Sensor and ECU troubles

[Admiral coFF33]

Hey guys!

recently picked up another FCD for the JZZ20.

This time its not a DIY job from Jaycar.

Its a Turbosmart FCD3 (for some reason not listed on their site)

Heres a diagram of what it is :






Now the way to wire it is this:

Red : Apply 12V power on an acc wire
Blue : Connect to wire going INTO THE ECU
Yellow : Cut wire COMING FROM MAP sensor and connect
Black : Ground


This setup is a basic layout and is identical to my original FCD i bought from jaycar.

Now.

After fucking around with 2 ECU's ive found the following:

1.
When FCD is not connected the ECU and engine will RUN FINE

2. When FCD is connected the Engine will barely idle and Check engine light is on and engine turns off after around 2 - 3 seconds


I fucked around with my multimetre and found the following:

1. At idle the map sensor wire when connected to ECU and not running through FCD has 1.3v with a bit of throttle that comes up a tad ~2.1- 2.2 whatever.

2. At idle with the FCD yellow wire "spliced into" the map sensor wire , but the map sensor wire still connected as per normal, the BLUE WIRE (meant to be going back into ecu to complete the FCD circuit) is displaying 6.3v-6.4v

3. revesing the yellow and blue wire (so blue is input , yellow output) the engine will run , but check engine light is on

4. with the reverse method, the YELLOW WIRE shows 0v


So as you would expect this is causing the ECU to think its WAY WAY WAY past the fuelcut and is shutting the engine off.

the FCD is made to clamp and reduce the voltage below the fuel cut level.


Can anyone tell me if they have come across this before or what i could possibly do to make this FCD work?

PLZ dont tell me to bin it, please dont tell me to use my original Jaycar one as thats not a "fix" its just a cop out.

cheers all


PS. : HERES THE FITTING INSTRUCTIONS FROM TURBOSMARTS SITE :
http://www.turbosmartonline.com/inde...ownload&id=114


PPS:


I have been told PLUG W - PIN 2 (PIM- VAC SENSOR) is the map sensor wire




thanks again

[EldarO]

PIM is the right wire, from memory its pale green.

[Officer Doofy]

Does it have anyway to adjust the clamp voltage?
Can you apply 5v to the yellow wire with the engine off and on acc and measure the clamp voltage from the blue wire.

If there is no way to adjust the clamp voltage maybe its not meant for a 1j, as you know 6v plus is way to high.

[Admiral coFF33]

Hi Officer Doofy,

Yes , the FCD3 comes with CLAMP . RELEASE . SLOPE

No matter how i modify the dials from 1 to 10 they wont bring the voltage down past 5.9v

[Officer Doofy]

It looks like a cool unit with the overboost feature. Setting 5 sounds good for you with the release higher depending on what boost you want to run. Slope im not sure.

Can you put release on highest setting and apply 5v to the yellow wire to see what the "real clamp" voltages are on the blue wire. I think yours may be wack.

Care must be taken playing with wires, always have acc off untill you are ready to check or you may retire the ecu before its time.

[Admiral coFF33]

i always disconnect the batt when playing with ECU anyway

ill try 5v on the FCD this arvo

[wilbo666]

It sounds broken to me. Or incorrect for your usage.

I'd really avoid doing the things that you have done as well. Sounds like a good way to fuck an ECU if you ask me

6+ volts up a 5V input... not the best eh

Cheers
Wilbo

[Admiral coFF33]

well after fucking around a whole heap

i ended up re-setting up the Jaycar device.

and with master Wilbo666's help

it works fine


respect to $20 items and Disrespect to expensive items

[bungs]

so what voltage did the jaycar fcd end up being? i checked mine today, 4.24volts cut (changing the 3.9kohm resistor to 5.9kohm) and it still hits the boost cut??? Might try 4.1volts tomorrow..

[bungs]

Fed up with it. Changed the 680ohm resistor to 300 and the 3.9kohm resistor to 4.3 for a clamping voltage of 4.1V. It clamps fine, but at idle it's actually changing the voltage from 1.3(without FCD) to 1.45V. This makes the car idle at around 450rpm and is mega rich.

Gonna ditch it and get something else. grr

ps. Even without changing any resistors and leaving it with stock components, it still alters the signal from 1.3v to 1.45v. What a pos

[Admiral coFF33]

Bungs,

Wilbo made me check many voltages.

the FCD works find now, Basically Diode 1 (D1) was fucked out and causing voltage spikes.

remove D1 and test volts between 12V in (wire) and pin 1, should be 1.3v
if its 1.3 , replace D1 with a new diode

[wilbo666]

Bungs,

Wilbo made me check many voltages.

Like 3 places many is it?

the FCD works find now, Basically Diode 1 (D1) was fucked out and causing voltage spikes.

Half right

D1 was fucked, it was short circuit (as opposed to a diode). It wasn't causing spikes tho

D1 is being used as a protection diode to the +12V rail (ignition) so when it was short circuit it was trying to pull the input line to ~11.4V!


If I were you I'd check to see if the buffer op amp is working... and then check the 'comparator' stage if it is...there isn't much to em!



Cheers
Wilbo

[PsyCo]

I've got a FCD 3 lying around that i scored for nothing.
I knew there was a reason turbosmart ditched it for the FCD2. I've sold plenty of FCD1's for 1jz. They look & work just like a boost tee bleeding pressure off the MAP.

I'm fitting a Greddy Emanage blue into my new project which has FCD built in.