Restoration decisions on my 280Z

[jemhood]

I have a 1975 280Z that I am in the process of restoring. I bought it from a guy who was planning to replace the l28 with a v8. The body is not too bad but the motor and transmission were out and according to him it was not running when he bought it. I've stripped this car and am in the process of repairing some relatively minor rust areas and getting ready for paint.

I also have a 1978 Z with a salvage title. The body is rusted very badly but the motor runs and has good compression. It is in pretty good mechanical condition and I know that it will run. There's a problem with the fuel system retaining pressure but I don't think that is a big problem.

My question is how much of the original '75 should I keep. I'm tempted to take everything that will transfer from the '78 to the '75. I know that gas tank is not compatible. Although I've considered changing the spare tire tub so I could use the '78 tank, but I think both gas tanks are in about the same shape and will need to be de-rusted and sealed. And I like the idea of a full size spare. Is there anything else that won't transfer? I guess it would only be bolt holes lining up and that sort of thing at this level of replacement.

So my plan is to take the dash, wiring harnesses, ignition, ECU, engine, front and rear suspension, transmission, etc from the '78. Other than the dash I will keep the '75 interior as stock as possible.

Alternatively I could go with the '75 parts and keep everything original. It will be more work and will likely be more expensive. I know that the wiring harnesses need work and that is probably why it wasn't running. I found several burned/broken wires as I was stripping the car.

I'm looking for opinions and a sanity check. Am I missing something? Is it a mistake to do what I'm planning? What would you do? I should add that the purpose of this car is for me to drive and have fun, not to show.

I've been reading and learning on this forum for months. It's a great resource. Thanks everyone.

[EuroDat]

If you know everthing on the 78 is in better condition, then I would go down that road and use the parts from the 78. The wiring is burnt in the 75 so there could be damage in switches etc. It wont be original, but if that is not an issue it should'nt hold you back.

The efi is Bosch L-Jetronic and is know to be reliable. I would at least have the injectors cleaned and checked. That can make a big difference to the overall running. Since you said the tanks are rusted the injectors are most probably dirty and partly blocked.

Are th dashes in the same condition with cracks and such?

[jemhood]

The '75 has two pretty large cracks. The '78 has a full cover so I can only assume that it is in pretty bad shape or the previous owner wouldn't have put the cover on. I think the '75 has an ammeter while the '78 has a voltmeter. That's one reason I was planning to just replace dash and all. I don't know how much trouble it would be to change the '78 harness to work with the ammeter. I suppose I could just change out the meter, assuming that the wiring is the same. I still need to do some research on that.

Good advice on the injectors. I start the '78 once a week and it's running pretty rough. I've seen several suggestions to use witchhunter.com for injector cleaning. Their site says $21 to clean and test. I guess that's the way to go.

[EuroDat]

I have also heard of OKinjectors. They do a lot of old system injector cleaning and can match flow your injectors. I have not seen any reviews about them in this forum. Maybe someone can give us their views?

http://www.okinjectors.com/#!__my-website/gasoline-injector-service

http://www.hiperformancestore.com/Ljetronic.htm

There is a really nice post on fixing a dash by BD240Z. http://www.classiczcars.com/forums/thread23919.html He did a top job on it.

I dont know what the differences are in the wiring diagrams. You could download the FSM's from both models and check the differences that way. http://www.xenons30.com/reference.html

[Zed Head]

A couple of years ago a guy tried to swap a 77 harness in to a 78 and had problems. There are differences that are hard to figure out, for example the fuel pump relay setup and the voltage regulation. Compare the wiring diagrams before you decide to start tearing things out. Might be easier to just fix the bad 75 connections and individual wires. The EFI harness is a complete sub-assembly and is identical, I believe, so swapping just that sub-harness and leaving the body harness might be an option.

The doors are different between the two models you have. Most internal parts won't swap, but the door handles and trim parts will.

The ECUs and/or AFMs might be the same part number, depending on where the car came from. The brake wheel cylinders in the back are different but the suspensions will swap over as complete units, brakes attached. The 78 cylinders are cheaper and of a better design, dual piston versus sliding cylinder. The windshield and hatch will swap. Heater parts may or may not be different.

I had a similar situation, a 76 runner, and a 78 parts car.