Engine will not start

Hey guys,

I have a 1990 300zx with a JDM replacement motor.

I had a full buildup of corrosion in my radiator, so I decided to remove it and flush it with water so i can start flushing the coolant out in process of draining and refilling.

So after I reinstalled everything after a radiator clean/flush, It ran for a bit but then died and I couldnt get it to start again. the car will crank but wont start. Several sites advised me to check the ECU, and found that its giving code 11, Crank Angle Circuit.

I have the older PTU, which I read goes bad and I should get replaced by Nissan as it was on their list of recalls. Before I proceed on replacing my CAS, should I try to replace the PTU?

I also found that the ignition coil relay could also be a problem. I got the engine and some components wet under the hood which Im probably thinking I accidentally shorted out. Is there any way to short out the CAS by cleaning it on the outside, or getting water on the PTU?

Lastly I checked my fuel filter to see if It was getting fuel. I replaced it with a fresh one, and when I went to check if there was fuel in it there was. So I know its getting fuel.

Troubleshooting I checked the TPS, and sensors on the upper radiator inlet, there are two on the front of the motor. Took them off and cleaned them up. I also cleaned all connectors and pins on both the CAS, and TPS sensor to ensure that they were getting connection.

I also cleaned the MAF as well, took it off and reconnected it after cleaning the pins and connectors.

The Z cranks, and I can hear the fuel pump kicking in, but it just cranks and cranks, and does not fire.

Im also confused about the coil packs (ignition coils). When I order one I have to order 6 correct? Because these are what fire my spark plugs?

Also, if I get a new CAS and PTU can I use any of the years or a N/A version? They all look the same, or do I have to get a TT specific versions?

Thanks you for any help and for helping sort this out.