Alright guys this is going to be a bit lengthy, but I'm hoping by giving as much info as possible the clues will be there and you will have a better idea, maybe I'm looking too hard at one thing.

Okay I got this 1978 280z about 2 months ago. The car hasn't touched the road in 12 years and hadn't started in who knows how long.

First I got a battery and hooked it up. The brake lights or night time lights were permanently on and the headlight switch would turn on the lights (it looks like someone put in new wiring to all of these things to bypass switches or fuses). The voltmeter also was the only gauge that worked. With the keys in the car there was no signs of life from turning the key to accessory. NO lights sounds, nothing.

I changed the oil, spark plugs, filter, fuel filter, dropped the fuel tank and cleaned it out, switched out some lines, the fuel filter, added another in line fuel filter and put things back in. Once I did all that I turned the "crank bolt" and it was not seized. After that I gave the ignition a full turn, and nothing happened. Went back to the engine bay wiring. After watching a random youtube video I saw that two wires that were just laying in the engine bay were supposed to be hooked to the battery so I rigged them back in the terminal. I tried starting it again and there was life in the ignition. I sprayed some starter fluid in the intake and it started up and died shortly after (I was by myself so I could not continue to spray it to keep it going). Mind you still no gauges or anything worked.

Then the ignition started to act funny. I would try to turn it and nothing would happen. And on the second or third time it would start again (with starter fluid). Then it would shut off, I know the fuel pump didn't work at this time. So sprayed some more starter fluid and tried again. This time the ignition didn't work until the 4th or 5th try. And upon the final attempt the ignition did not work at all. I also noticed the volt meter (the only gauge that worked) is no longer working.

At this point I tried to clean up some electrical and fix some things for longevity. I did a fusible link delete with the Maxi fuses. I cleaned the positive starter terminal, took the wires off, sanded the o ring terminals, and de gunked everything and put them back on. I took off all the grounds cleaned the o ring terminals and sanded the paint where they were attached and re attached them, one with a new 4 gauge wire to replace an 8 or so. I took the two wires connected under the fuel pump and plugged the battery straight to it through the bullet terminals and the pump made no sound. I cut the terminals off and connected straight to the wires and the pump started to prime, so the connections/ wiring was bad there. Then I replaced all the cylinder fuses in the passenger kick panel with all new fuses. Then the ignition still did not work.

My next step is to take off the fuse box kick panel, get some connection cleaner and "dialectic grease" take the fuse box completely off (if possible) clean all the connections and prep them, and see if that makes it work.

If this should not work, does anyone have an idea of where I should start looking to tackle next based on the things that have shown so far. The volt meter being the only gauge that did work, and now it doesn't. The ignition slowly stopping working. These are two clues that I just don't know what they mean.

Congrats on getting a Z and welcome to the group.  There is probably more that one thing that needs to be done in order to start the engine and keep it running.  You can download the FSM and a beautiful color wiring diagram to really help.  As far as the electrical portion goes, there are a few very knowledgeable electrical guys here ( I'm not one of them), but what anybody who is bringing a old car back to life has to do is,  go through and clean and check  E V E R Y  Single electrical connection.  That means the dash harness, the EFI harness, the cabin harness and the engine bay harness along with everything that is attached to them.  40+ year old wiring oxidizes, rusts and corrodes with time and moisture.  DeOxit electrical cleaner seems to be recommended often.  If you do this in the beginning it will help you solve a lot of issues down the road.  It's time consuming but well worth it in the long run IMO. 

Edit to say that previous owners have often hacked the wiring.  Those are always fun to discover and correct?

Edited May 25, 20195 yr by gwri8

20 hours ago, tleverett said:

And upon the final attempt the ignition did not work at all. I also noticed the volt meter (the only gauge that worked) is no longer working.

The voltmeter should always work even with the key off.  Sounds like you've lost connection through your main fusible link.  there's a fuse also but I can't tell which one it is.  There's better diagram below this one.

I checked the voltage on all of the fusible links today, all have 12v going out.

Gwri8 where can I find the colored wiring diagram? I have the fsm in hard and electric copies. Still trying to find the relevant info in it

1 hour ago, tleverett said:

Gwri8 where can I find the colored wiring diagram? I have the fsm in hard and electric copies. Still trying to find the relevant info in it

You will find it here on this forum.  Look up at the Header with Classic Z Car Club on it and there will be a tab called resources. click it and look for the 77' color wiring diagram.  I know you have a 78' and the coil and voltage reg will be different but a lot of it still pertains.  Lots of other good stuff there also.

I did test the ignition switch, and the S post was not sending a signal anymore. Ordered a new switch, hopefully it will start again.