Can any one tell me how to get my car started I have a 1975 280z with a l28et 1981 280zxt swap in the process along with wire harness and ecu I need to install the ignition harness and according to this website I have to connect the black wire to some relays but a member of another z site told me I have an interlock relay and so I can't combine the two electric systems together to turn turn the motor on. And he also said that the 1975 280z was one of the weird cars from the four years of the 280z's...so I wonder what can I do to complete the swap.

I believe i also have the 280zxt underdash harness along with the the ignition relay and other connections for the gauges... hope I didn't make a mess about what I'm trying to explain

 

Which "black" wire? There's several...

This is an easy swap, and lots of info on this site:

https://www.zdriver.com/forums/240z-260z-280z-motor-swaps-non-v8-269/l28et-s30-tucked-like-stock-only-better-pic-heavy-30516/

https://www.zdriver.com/forums/240z-260z-280z-motor-swaps-non-v8-269/efi-ignition-setup-l28et-swap-27449/

and the Hybridz writeup: http://forums.hybridz.org/index.php?showtopic=34469

In a nut shell, yank the entire L28ET ecu harness. Most of the needed wiring can be done right to the white 4 pin (6 slot, 2 middle pins are missing) 280z ignition plug. See wiring diagrams from the FSM (I don't have time to find it right now).
#71 - Black (switched 12v) goes to Black w/ White stripe wire on L28ET harness.
#73 - Blue constant 12v goes to White w/ Black stripe for L28ET harness Fuel Pump Relay.
#74 - Blue fuel pump 12v goes to green L28ET harness fuel pump wire
#76 - Black start signal goes to chopped Yellow wire connecting to L28ET coil harness.

 

Going through some of my turbo swap pics, I found this, which should help w/ the swap:

 

That relay on my 1975 280z I dnt have that relay and the wires that are dangling were are they from? I have that resistor with the blue and green wire, we're are you connecting the green wire to? And the black wire from the ignition wire harness were do I connect it to? Does it matter that my car is a 1975 280z maybe if I take a quick picture of my relays you can identify which relays I have to connect wires to make it work..

 

Did you click on any of the links I posted? They will answer all your questions.

That plug in the pic is under the dash by the hood latch puller... take a look at your car and you will see it.

The green resistor wire goes to the stock tach plug that connects to the stock 280z ecu harness (it's a one wire white plug).... look at the pic.

Black wire on coil / ignition harness goes to switched 12v power.

I highly suggest clicking on the links I posted.

 

I have lookd the dash is off I looked and nothing is there(relay),the harness for for the resistor did you connect it to dash harness or 280z stock ecu harness? I've checked out the sites hybridz and the other links but doesnt seem to help... I've seen the diagram on this site the black wire has to go to the relay first and then to a switched power source could I get that from switch like in the switch like in the diagram? Or do I have to connect it also to the inhibitor relay if I
have it?

 

This is what I am doing:

Is this your first wiring job?

 

Yea it is when i got the car it had it already had the 1981 280zx turbo motor and harness was installed and ecu I just have to connect it but its the ignition harness is were I'm stuck and hope it turns on!!! What about you how far along. You on your swap? Does yours turn on yet?

 

read the write up for the 81 on hybrid carefully, it tell you everything you need to know.


I built and swapped the L28et that was in my Z and the wiring was the easiest part

 

skib how did u do the ignition wire harness wiring... explain to me please and dnt tell me to read the write up...cuz I have read it at least 10x unless I missed sumthing... what wires u used and were u hooked them up..

 

Bro... I DO think you missed something. This isn't complicated at all. I did a complete L28ET harness swap this spring, and even upgraded the harness to the Z31T ecu & maf. It's VERY simple as long as you have your wiring schematics and a note pad, and a BASIC knowledge of auto electrical systems.

I explained the ignition wiring in my first post. I don't get what you are still confused about....

 

the HBZ thread really has everything in it man, theres nothing that I can tell you thats not in there.


I used that exact thread to wire mine.

 

Yea you guys are right lol I just read it with a micro scope and missed somthing....sorry for the frustration I caused you both....lol :/ The switched power source dit u guys get it from the ignition?