1990 300zx NA All of a sudden stopped running and wont start back up

[1990NA]

OK so i just bought a 1990 NA 300zx 4 weeks ago and so far so good. I got an engine tune up all fluids replaced and new spark plugs. And today i took it out for a drive. It started just fine i drove it 25 miles on the freeway and as i got off of the freeway and stopped at the first stop light. Just before the light turned green i put the clutch in and put the car in first and just as i did that the car just suddenly shut off. I simply thought i had stalled the car being that i just learned to drive stick wen i bought this car 4 weeks ago but wen i went to start it back up it turns over but didnt fire up. Just in general the key usually has to be turned twice to get the car to start sometimes. Also sometimes wen i go to start it it makes a grinding hissy noise. I had no clue where to start looking to try and solve the problem and this is wat i know about it atm. Any ideas at all would be very helpful and ty in advance for the help.

[Z-owned]

The grinding sound would be your starter.

[evildky]

step 1. check ecu for codesstep 2. check for fuel pressure

most often it's either a spark issue which will come up as an ingnition code wihc means ptu, or it's be a cas issue which is a cas code, or it's a fuel pump or controller issue which sends no codes but you won't have fuel pressure

[1990NA]

Ive been reading on alot of forums and it seems the PTU is a common problem. Since i have a 1990 there was a recall from wat i understand. So should i check to see if i have the old one and replace it if its old?

[1990NA]

I ran a diagnostic on the ecu and it gave me the code 11. which is Crank Angle Sensor is wat i read. How would i go about checking that?