So I got my 86 300zx non turbo a couple months ago. Guy I got it from sold it because it wouldn't start. Said it might be the battery, timing or the digital dash computer. I noticed the fuseable link to the fule injector was fried so I replaced that and got a new battery fixed the termail ends. but when I got to start it the dash won't come on the headlights won't flip up the fule pump primes, and the car cranks but will not turn over. Not sure what to do don't wanna take it to the shop

Check for spark, fuel, codes, basically the basics and go from there.

yup, codes, spark and fuel. First thing check for codes. the dash might be bad but it won't keep the car form running and driving.

My guess is your Main fusible link is now blown. Sometimes it's labled as Battery link. This will not fix your Starting isssue, but it Should return power to the inside and the headlights. (it might not still, but i'm like 90% it will. You should know this issue needs to addressed, because those FUSIBLE links only blow when there is a short or some sort of power surge and let me tell you, they will blow again !)

Starting issue from a electical issue stand point- You need to get a voltage tester and check that its getting atleast 12v to the battery, as well as the starter and the altenator. Bad connnections can cause the car not to start, make sure your terminal connections are good as well as the main ground. Start there, then check the connections on the starter and the altenator. Get your battery tested, even if you got it a few months ago , any local parts store will also charge it for free (usually takes 30-45 mins). You can use a running car and jumper cables to charge it a little and try starting it since that will give you a continous 14v

How long has this car been sitting? My guess is the previous owner didn't bother putting fuel stablizer in so that's going to need to be drained. Notice I didn't talk much about Fuel related /spark related starting issues, most of the time it's electical. This is where you should look first , Good luck!

Checking for spark, and fuel and codes can help you locate an electrical issue when that issue is keeping the car from running. There are a lot of electronics in the car but learning that you have no spark for instance lets you start testing the electronic's at the cas, ignitor and coil. And you never simply assume the component is at fault you check that it's receiving the current, ground or signal that it should as well as checking that it is outputting the current, ground or signal or resistance that it should .

Sorry it took me so long to reply I wanted to try everything you guys suggested. I tried to check for codes but the ECU wasn't getting any power, same thing keeps happening the fuel pump primes and the car cranks but won't start, seems like it's not getting enough power I even tried to jump start it and still nothing not really sure where to go from here, car has only been sitting sense last summer.

No power at the ecu? Great, now all you have to do is track that circuit, ignition switch, relay, fusible link and wiring.

Yeah the ECU had zero power. Ill give it a go!

I just checked the main fuse box under the hood on the driver side and I'm missing a fuse for the clutch ignition and vacuum pump