lt12 piggyback wiring

[Omar]

Hi All
I'm new in this forum & need help to get the wiring diagram on Lt12s to 2jzgte Aristo wiring.
The reason why I'm using piggyback concept due to need to activate the idling, AT trans signal with factory ecu.

Thanks in advance

[Omar]

anyone please

[YLD-16L]

Hi Omar,

They have a number of wiring diagrams here:

http://www.microtech-efi.com/support/downloads.html

They have JZ series ignition diagram listed and the 6 cylinder fuel diagram for LT12S so that should help.

[SillyCarS]

hey i just finished wiring one of these up in my car to a 1g

can you explain why exactly you want the signal from the factory ECU? whats the benefit etc?

[YLD-16L]

hey i just finished wiring one of these up in my car to a 1g

can you explain why exactly you want the signal from the factory ECU? whats the benefit etc?

Probably to control the features the microtech can't.

My mate did the same in his STi so the factory ECU could control the idle and a few other things to keep it's factory niceness.

[SillyCarS]

oh ok

well in my 30 yr sillycar i think i can go without

so basically you trick the factory ecu, how do you stop it from making a massive error code list?

[YLD-16L]

oh ok

well in my 30 yr sillycar i think i can go without

so basically you trick the factory ecu, how do you stop it from making a massive error code list?

You don't generally (you could though), but because the factory ECU is only controlling the idle valve/motor and idle up for accessories and other ancillaries none of the errors it sees affect their operation in most cars - some of the really modern cars I think it would??.

Any of the more powerful ECU's negates the need for piggybacking though as they can make everything nice and work properly anyway.

[Omar]

I'm confused on igniter wiring. For lt12s the output with -ve signal. Plan to cut the wires inbetween stock ecu to stock igniter & join to lt12s wires

[chris davey]

ditch stock igniter.

get the 6 wires that were going from the igniter to the coils (these are negative)

connect these 6 wires to the x6 igniter output wires. remember that it is in firing order not 1-6.

Leave the positive wires on the coils as they will still be ignition switched by the stock loom if you piggy back it.

[Omar]

Chris,
I'm not using the x6.
If I'm use back the stock igniter, I should cut the wires from stcok ecu & join it to lt12 ignition out-put (-ve). Is it right chris?