1991 1uz -> 95 240sx (s14)

[Fries]

I've found this information for a s14 swap.

Which is EXTREMELY helpful for a wiring nooB like myself. However, I'm lacking the 4th plug that goes from the ECU to (?) the dash harness and relays. Also, don't have the Lexus relays. (which should be okay because I can utilize the nissan ones since the ignition systems are super similar)


Instructions for wiring a 1uz that I've found state that:

• +12V wired to pin (BATT)

• (M-REL) drives the Main EFI Relay: switches it on.

• (+B) and (+B1) both get 12volts when the Main EFI Relay is switched.

• Main EFI Relay appears to be working fine.

• (STA) gets a 12volt input from starter relay when the engine is cranking.

• (IGSW) gets a switched power 12volts from the ignition switch.

• You might want to find the check light (W) and use as an earth for a light
(switched power on the other side), tells you if the ecu is on or not.

2.1.2 In the wiring loom:

• Find the injector power wire, and connect that to relay / switched power. It’s
usually a striped wire. In the older motors it’s Black/Orange, newer engines it’s
Blue/Red.

• Find the power to the igniters, connect that to a relay / switched power, usually
the same colour as the injector power wire.

• Sometimes: the sensor power wire is loose in the loom, find it, give it switched
power.

It seems pretty simple except I need to see the wiring diagram/layout of the 4th ecu plug to the 4 plugs that come off it (28/16/22/34 pin plugs.)

Here's some images of my harness/ecu

ECU with Relays (unknown) on the side.



IL1 and the other plugs (no idea what wires are in them)


IL1

 

[Fries]

Am I over thinking this?
Can I just apply switched power to IL1's
IGSW wire//B+ wire?
Do I need the M-REL wire if I won't be using the main EFI rely and I'll be utilizing the Nissans constant 12V and then make a custom pin for the BATT pin #26 (4th ECU plug which I'm missing)??

I'm just unsure about applying power to these wires if they're supposed to get them from another area. Does splicing in power wires to the main 3 plugs affect anything?

 

[Fries]

Will this work for wiring the ECU or am I not supposed to add power to those cables??


Can I eliminate the need for M-REL if I'll be using spliced in switched power at these locations and giving the ECU constant power from the Nissan harness?

Note: IL1 is not the plug that goes into the ECU, its engine harness to interior.

 

[Fries]

Figured it out, gonna just purchase a relay and run it the proper way.

 

[pajman]

Hi I've been meaning to post this for you , it might help you
http://lextreme.com/article/1UZSingleSpeedFuelpump.jpg

 

[Fries]

Thank you! Super helpful actually!

 

[Doubledip]

Just use the Nissan relay and change it from neg triggered to positive triggered from mrel wire
It's pretty easy to do a 1uz into a Nissan as the wiring is pretty similar
Do em with my eyes closed

 

[Doubledip]

U should really use the mrel wire as it resets the idle motor and maybe afew other things when u turn engine off ofr next time u start it
Otherwise u might run into problems with idle at startup

 

[Fries]

Just use the Nissan relay and change it from neg triggered to positive triggered from mrel wire
It's pretty easy to do a 1uz into a Nissan as the wiring is pretty similar
Do em with my eyes closed

Yeah that's what I'm gonna do. I just found out the FC wire doesnt pull enough to trigger a relay. I'll splice the M-REL into a relay that will ground out the nissan fuel wire which will turn the pump on.

Thanks for the help duder's.

I'm pretty confident that I've got it down. Just a little nervous to start putting power to stuff. Don't want to mess things up.