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Discussion Starter · #1 ·
I have recently bought a 1983 Datsun 280zx as a project car it needed a lot of help and right now I’m just focused on getting it to start.
I have replaced the fuel pump, fuel filter, ignition coil, and starter and I went to crank it over and it started for a few seconds then died. I tried to start it again and it wouldn’t so I waited a minute tried it again and it started for a few seconds and died again.
I have read quite a few forums and I haven’t quite heard of one doing what mine is doing. If anyone could help that would be great I’m new to the Z cars and don’t know a whole lot.
 

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I wonder what the top side (from the filter outlet to the injectors) of the fuel system looks like.

When I was messing with mine, if I disconnected the hose from outlet of the filter, I had a lot of sediment/rust(?) come down from the fuel rail. May have been deteriorating fuel line too, not sure.


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did you drain old fuel and coat the tank prior to trying to start the car... these z gas tanks like to rust and when they do they clog the tiny screen in the fuel pump as well as the fuel filter I recommend you check fuel pressure before digging into anything to rigorous get a fuel pressure gauge and put it in between your fuel rail and fuel filter and see how much pressure your getting (should be around 36psi).
 

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Get a fuel pressure gauge and check the fuel pressure. You will have to install it between the filter and the fuel rail. You can get the fittings at Lowes and some extra FUEL INJECTION fuel hose. Yes there is a difference.
 

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Discussion Starter · #6 ·
I wonder what the top side (from the filter outlet to the injectors) of the fuel system looks like.

When I was messing with mine, if I disconnected the hose from outlet of the filter, I had a lot of sediment/rust(?) come down from the fuel rail. May have been deteriorating fuel line too, not sure.


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I unplugged the cold start valve and tried to start it and it didn’t then I plugged it back in and it started for a few seconds then died so it was running off the cold start valve for a few seconds then dying. Then took an injector out of the manifold still connected to the the fuel rail and plugged in and nothing came out. It had gas sitting it it for 20 years so I’m presuming it got all gummed up, I’ve bought more injectors and they will be here next week that should hopefully solve the problem.
 

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Discussion Starter · #7 ·
did you drain old fuel and coat the tank prior to trying to start the car... these z gas tanks like to rust and when they do they clog the tiny screen in the fuel pump as well as the fuel filter I recommend you check fuel pressure before digging into anything to rigorous get a fuel pressure gauge and put it in between your fuel rail and fuel filter and see how much pressure your getting (should be around 36psi).
I disconnected the fuel pump cause I needed a new one and didn’t connect it back to the fuel tank, I got a small gas tank and ran clear tubing from the supply to the fuel rain, and from the fuel rail to the return line and back into the small gas can do I can see if it has pressure and it does seem to have adequate pressure.
 

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Put a pressure gauge on it. That is how you check fuel pressure. Fuel pressure needs to be correct. Don't guess. Guessing costs money. You NEED to remove all the injectors from the rail and clean the rail out. You are guessing that it is running on the cold start injector. After about 8 seconds the cold injector wont do anything. Your thermo-time switch has to be working for the cold start injector to work. Guess where you find how to test it, yep.......in the FSM diagnostic procedure. I don't even know if an engine will start on just the cold start injector. There are other things that will cause your injectors not to function.
 

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Sometimes the fuel pump will only work while cranking. There are two sources of power for fuel pump. One during cranking and the other after starting. It could be that the later is not providing the power for the pump.
 
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