300zx tt manual simply will not crank it is not a mechanical fault but a electrical,when I turn her over the dash lights come up then disappear almost instantly ive tried the pus and the cas crank angle sensor not the crash assisted steering as 1of ya said lol please only help if u no what your saying I literally know every nut and bolt on her.however I no nothing about her eletrics

SOURCE: no start 1992 300zx

Did you try rotating the CAS input shaft? Remember that the cams spin at half the speed of the crank, so a full spin of the CAS is actually 720 degrees. It could be that the CAS is 360 degrees out of phase and causing the car not to run properly. Unbolt it and remove it carefully. Rotate the input shaft (the part that mates with the cam) 360 degrees and put it back on, and see if that helps.

Also, just making sure, when you double-checked the cam timing marks, you did verify that in addition to the four cam sprockets being aligned properly, the crank timing mark is also aligned correctly, right?

SOURCE: need to know what the warning light on dash means

The flashing dash light is a warning about a failing system, most likely the fuel system. On mine it was the oxygen sensor on the way out. You need to do the diagnosis process with the ECU and this will report back the code that will tell you precisely what's the problem. You'll find the ECU diagnosis procedure here at the 300ZX online factory service manual.
Hope this helps.

SOURCE: my 94 300zx tt wont start changed ecu cas and ptu

check timing, see if belt may have slipped out of timing, and need pressure tester to test pressure where the fuel goes into the fuel filter. check for vaccuum leaks.

SOURCE: Distributor wont spark

check the fuseble link.
you can measure it, and make sure the contact are clean and secured.
the other thing is the check the ignition switch, make sure you have 12v going to the switch.
check thermo switch on top of the block.

SOURCE: 300zx tt 1990 wont start

Probably crank sensor,but could be fuel pump issue.