2JZGTE in MA61+Power FC - ECU not holding data

[Gabe]

Ok, if anyone here can help me out, i'd be hugely greatful.
I have a 2JZGTE in my MA61 and have just fitted a Power FC.

As expected, the car fires into life and drives no issue on the 'base maps' provided. However, when a change is made, any change, from a fuel map change, to simply changing the hand controller contrast. The changes only appear to stay in memory while the car is powered on. Turn the ignition switch off, and on again, and the ECU goes back to it's original factory defults.

Now obviously, the wiring loom has been altered somewhat to wire it into it's new home, so i'm thinking a wiring problem may be possible. I have checked that there is a constant 12V supply to where it should be on the back of the ECU plug, and all the grounds appear to be intact also.

Just really wanting to find out if it is an ECU issue, or a wiring issue. I'm fairly competant with a multimeter and scope if someone could point me in the right direction? I'm itching to get out and start tuning the thing....
Thanks

Gabe

[sideshow]

its a wiring issue i have seen this prob before but didnt get chance to fix it

croyden autosports fixed it but im sure they wont tell u the fix over the phone

[Gabe]

its a wiring issue i have seen this prob before but didnt get chance to fix it

croyden autosports fixed it but im sure they wont tell u the fix over the phone

Yes,
After some digging, I have read about the Power FC requiring power to be maintained for a second or so after the ignition is switched off. Or something to that effect. Not exactly sure how to do this however.

Apparently, some immobilisers cut all power immediately, this may be the case in my setup.

Any ideas?
Anyone?

[chris davey]

Just a thought but what about those jaycar things that keep the interior lights on for an extra amount of time when the door is closed. May be able to rig one of them up to the constant 12v so that when you turn the car off the power stays on for an extra 5 seconds or something.

[boldy]

Assuming the PFC won't be controlling spark or fuel when the ignition is off, why don't you try putting a nice big capacitor across the 12V supply? Might just hold enough charge for that second that you need.

[wilbo666]

Yes,
After some digging, I have read about the Power FC requiring power to be maintained for a second or so after the ignition is switched off. Or something to that effect. Not exactly sure how to do this however.

Apparently, some immobilisers cut all power immediately, this may be the case in my setup.

Any ideas?
Anyone?

1JZ ECU (and I'm pretty sure the 2JZ ECU) take IGN as an input to the ECU. From that it switched the MREL (master relay). The reason it does this is so that it can keep power to things like the ISCV after the ignition has been switched off (ISCV is opened fully when the engine is turned off!).

The ECU leaves the MREL on for a small period of time after IGN has been switched off. As the ECU has constant power it can do this

I'd suggest that you could try getting you power FC switched power from the MREL relay ...

Cheers
Wilbo

[JP]

yep,

I agree wtih Wilbo, check that you have your car wired to utilise the MREL like it is in a factory setup. That's what I had to do with my JZX100 VVTI motor in my wagon for the PFC to retain it's settings.

[Gabe]

Thanks for the help guys,
The car wasn't wired with a MREL at all.
I wired in a new relay and utilised the MREL output from the ECU to drive it and viola, the Power FC stays powered up for a few seconds after the ignition switch is opened and retains it's changes.

Time to tune....