91 300zx Turbo idle issue

NO YEAR CAR told is it a car ?
NO car maker told, wow, a toyoto or Volvo ?

google has zillion hits for Volvo .so lets with that.
ahhh 2.4 t is (turbo engine)single or twin?
made 2000 to 2018, S60, s60R and S60L and more.

guessing it:

2497 cc B5254T12 turbo I5 (1 turbo right not the twin,)
why make me guess YEAR and get exact engine correct
or
2400 cc D5244T10/T11/T15 twin-turbo I5
Engine is Dead, , starts/ and stalls' so both keys do that?
the IMMO lamp glows wrong and key is bad? "security lamp"

I can not decode "won't stay start, when shift gear."
yes I get the idea of stalls yes.
does that mean it does start OKAY and idles all day if just doing that."? in park?
or idles all day but shifting to PRNDL, drive , REVERSE or LOW
the engine stalls in any gear well that can be many things.
I that means engine power is super low, (as in pathetic)
1:Low fuel pressure (use a pressure meter to check it)
2: scan tool shows bad MAF OR MAP sensors.
3: spark plugs10 years old?
4: idle controls dead, IAC/ISC.

check all fuses
and scan the PCM, and for sure at idle if it does in PARK.
can I assume transmission is auto not manual shifted?

I do believe you are correct, but here's how the system works. You turn the switch on, the computer is activated, the temperature sending unit, sensor sends a signal to the computer that it's cold so the computer sends out a signal to the engine to go into cold start mode. The fuel is enriched into the cylinders by raisin the idle just a bit placing more fuel into each cylinder, and the idle is advanced by a little electric plunger at the throttle body. Once the engine has warmed, the water temperature sensor sends a message to the computer to take the engine out of cold start mode and into normal run. Now you can understand why the temperature sending unit/sensor is so vital to proper starting procedure. Replace the temp sending unit/sensor and she will work just fine. School's out. Time to go to work.

I do not know your vehicle but in that time frame a lot of cars used what is called a ballast resistor. During start it was shorted allowing the coil to output more power, once the engine came up to speed about two seconds the short was removed. Shorting simply means bypassing the resistor. I hope that helps.

There can be several reasons for this. You can have worn valve stem seals on the valves, which may change with warm oil, or you have worn oil rings in the cylinders.

A compression test when the engine is cold would reveal if the piston rings are worn. Another possibility could be a bad head gasket which leaks oil when cold and then seals when the heads warm. A compression test would also diagnose this.

it will have codes but the scanner in use doesn't have the right protocol for reading them
Indicates a faulty ambient air temp or BARO sensor so there will be codes

60psi cold / 30-45psi warm is ideal. I've seen (with that mileage) 45 cold/ 20 warm and that's acceptable - anything less start thinking about a new oil pump.

Could be the fast idle sensor check to see that the vacume line is hooked up properly.

The bad ecu blew the isc motor

that is not a probelem it is the fuel system warming the engine and turbo
you should always warm up a turbo car before jumping in and taking off and cool the engine before shuting it off turbos are the most temprelental engine part there is. those steps will prolong the life of the turbo and engine. my starion with the g54b 2.6 does the same thing

Problem might be the air control valve, it's located at the right side rear of intake manifold and has a hose going to the air intake duct from the air cleaner, as a test you might try pinching off that hose when the idle is a problem.