ScCoghill

My 82 is suffering initial start up issues after sitting a couple of days. Here's what's happening:
1. I turn key on and the fuel pump pressurizes rail. I try and start it but it won't fire off. Repeat the key on routine and it will start after a couple trys. I saw this on a forum awhile back and I did step 1. It appears to be fine, but before I pull the Cold Start Valve and clean (How to do this? Gasket issues?) I wanted advice. The car runs great once it starts. Here is what the former post said to do...
An n/a rough cold start is either a faulty thermotime sensor / cold start valve, or faulty / leaking air regulator.

So:
#1: After cold starting, pinch hose between throttle body and air regulator. The idle rpm should drop. If not, the air regulator is not functioning (stuck closed). If it does, move to following step:

#2: Pull cold start valve & clean. Start car, no change: test thermotime sensor (Heat / Ohm test).

Also, where exactly are the three harnesses mentioned in the FSM to check at? Are they on the drivers lower left side panel by my clutch pedal?

Thanks,
Scott Coghill

NismoPick

First you need to check static fuel pressure... is the fuel pressure leaking down when the engine is off? Is it coming back to ~35psi when the fuel pump primes?
Second, you are referencing harnesses in the FSM, but not by name or location, so I don't know specifically what you are / aren't looking at. Here are some good reads and a screenshot of the thermostat housing sensors.
https://www.zdriver.com/forums/280zx...problem-38252/
https://www.zdriver.com/forums/280zx...problem-38793/

There are 3 sensors...

#1: Water temp sensor for dash gauge
#2: Water temp switch for the aux fan
#3: Thermotime switch for the cold start valve.