ive got an 82 z28 with crossfire injection, i also have a tuneport 305 and the complete harness from the donor car. heres the problem the donor is a 91 gta. i need to know if i change the motor out will i have to use the harness from the gta interior, or can i just replace the computer and switch it out at the fuse panel for the engine compartments harness. i know i will have to change the fuel tank but thats not a problem because i have the tank and the lines for that also. if anyone can be of help i would greatly appreciate it. thanks del.

 

Personally, I changed out the dash harness. Created a couple of problems with the differences from the dash to the rear chassis, but I got through it.

I've "heard" that ECM to dash is a simple change-out, but looking at the donor and receptor schematics, I saw differences beyond the ECM that led me to the dash swap. I may have been wrong.

A note on the engine -> ECM harness: The pass-through at the kick panel is larger on later years than on the '82. I just took a flat file to the hole (fender removed) and made it big enough for the later harness grommet to fit.

 

You probably are going to be well off to get the service manual for the 91, the service manual for the 82, and answer your own question.

Most likely, you will find the least work in adapting the harness to your car and replacing the original wiring with the GTA wiring as applicable (like starter wiring) except for the drivers side battery... Will you have to use the interior / dash wiring? No.

The plugs in the dash wiring going to the ECM & engine wiring are probably real similar to an LG4 car, so there will be some things you'll need to add since it's EFI and some that are exactly the same. If the TBI in 82 used a lamp driver module to run the SES light, you'll bypass this and run the lamp directly off the ECM. I'm not sure if the 82 had an elec. fuel pump in-tank, but you may be able to run fuel pump power through the stock car wiring.

Basically if it's in the 91 and it's not in the 82, add it. If it's in the 82 for the TBI and can't be used for the TPI, bypass it / leave it alone.

There's a lot of "little questions" that'll come up as you get into the project. I suggest documenting your wiring and getting the 2 service manuals and figuring out 90% of it, then you'll just need to figure out a few little things, and before long, you'll be injected