Hi everyone!

I own a 1981 280ZX 2+2 N/A here in Australia.
I have taken it from previous restorers (which never got to finish) and have taken it upon myself to restore it since its last time running in 2018.

Context
I used to be able to put the key into the ignition which the dash would do all the fancy checks and then show the "OK" symbol on the dash then start it up and it would run. However, I have since been restoring it cosmetically by unplugging all the dashboard connectors (to refurbish the dashboard) and plugged them back in. I also have removed the radio and casette player leaving only what i presume to be the radio connectors unplugged (they are the thick white blocky connectors with 6 pins)

Problem
The problem now is that when I put the key into the ignition and turn it to ON the dash no longer has the green "OK" on the display instead its a bright red square, my fuel gauge always says its low on fuel (and the low fuel light comes on). Also the fuel pump doesn't prime. Now i can only crank it but it just wont run.

Troubleshoots:
-Took out the mass airflow sensor and checked the resistance as per the manual it is OK
-Supplied voltage and checked all of the fuel pump relays which click and have continuity (from COM to N.C when coil is on) and have continuity at (COM to N.O when no voltage is supplied at the coil)
-Checked all the spark plugs from cylinder 1-6 all of them spark.
-Checked continuity at all of the fuel injectors which all worked.
-replaced the fuel pump, it "clicks" when its on but no priming. When I turn to ignition the pump clicks on and off (i suppose it is running)
-I am working towards unplugging the engine control unit and then checking the pins as per manual.
-took out the air flow sensor and sprayed starter fluid which the engine only ran on the starter fluid.
-Changed the oil (did not touch the oil pressure sensor/switch)
-Changed the fuel filter and topped up with fresh fuel.

Theres air, and spark but no fuel?

Diagnosis
There must be something wrong with the electronic system within the car in regards to starting? I took a hose connected to a sauce bottle which i connected into the fuel rail inlet (Ive attatched a photo) which is usually where you can test the fuel pressure connecting to where the fuel filter flows the fuel OUT. I then tried to start it but the fuel won't go down or get sucked which I believe the car is refusing to take fuel into the injectors and squirt it.


Ive been looking at the schematics and the logic flow of the fuel management system and the cold start fuel management system and I think ive done something wrong when wiring back the dash which dosent recognise any fuel, leading to false readings to the airflow sensor which dosent make the fuel injectors squirt fuel into the system?

I would really appreciate if you guys could help me out on this one, I just want the engine running like before so i can maintain it mechanically!

Thanks!

 

Have you installed a pressure gauge in the fuel line after the fuel filter like the manual instructs you to do in the diagnostic procedure to see if you have fuel pressure. Dont assume the pump is running, prove it. Dont assume you have fuel pressure, prove it. You could have a bad pump relay, bad connections, bad ground.
The way the system works is the pump will start and run for a few seconds when you turn the key to on. The fuel injection system should show about 36 psi and should hold that pressure. Try and start the car if you have pressure and the pressure should remain in that 32-36 psi range. If it does not you need to do the diagnostic procedure to check the electrical side of your fuel pump.
The fuel rail will not suck up fuel from a bottle, it must be force fed by the fuel pump.
What ever your dash issue is does not have anything to do with the fuel system unless you have messed with the wires from the ignition switch. You can remove the instrument cluster from the dash and the car will still run. Check to make sure you have all of the connectors on the back of the instrument cluster plugged in correctly. The round one supplies the power to the instruments.