Odd Starting/Idle Issue

[Downeaster1]

Greeting all, and thanks for all the help in my last post. I have a new issue that I've noticed. Typically, the car starts and idles like a champ. Zero hesitation and pulls strong if I start it cold. After warming, if shut down and immediately started back up, it will idle erratically/not start. This is just seconds after running smooth and normally. Any ideas? I'm kind of lost at this point.

Things replaced recently (with new parts):
M50 Fuel Injectors
Timing Belt (w/ Water Pump)
Spark Plugs
Fuel Pump (In-Line)
Fuel Pump (In Tank)
Intake Boot
AFM Unit
Idle Control Valve
Idle Control Module

I've unplugged the cold start valve to no luck. I'm going to see if the valve is leaking next, but that is where I'm at so far. Any insight would be great. Thanks!

EDIT: Also, it's a 1986 325e.

[MrBurgundy]

pull the vacuum line on the fuel pressure reg and see if there's gas in it when the cars warmed up.

[Downeaster1]

pull the vacuum line on the fuel pressure reg and see if there's gas in it when the cars warmed up.

Yes sir, 33psi.

[Downeaster1]

I've conducted a fuel pressure test; the pressure is good across the board and dips down when the vacuum line is disconnected from the fuel pressure regulator. Still not having any luck with this, as I've virtually replaced the entire injection system at this point. So far, I've replaced (with brand new parts):

M50 Fuel Injectors
Timing Belt (w/ Water Pump)
Spark Plugs
Fuel Pump (In-Line)
Fuel Pump (In Tank)
Intake Boot
AFM Unit (Air Meter, set to factory spec, 2 3/4 turns from tight)
Idle Control Valve (3 turns from closed)
Idle Control Module
Coolant Temperature switch (yellow connector)
Coolant Temperature sensor (blue connector)
DME (with a factory new unit)

The symptoms are:
When totally cold, the car runs, drives and idles perfectly. After about 10-15min of driving after the car has reached operating temp, all is still good. Continues to drive, idle and run perfectly. However, if I shut off the ignition and attempt to restart it before it is able to cool down completely, it runs like complete crap. This is just seconds after it was previously running perfectly. It barely idles / almost stalls / does stall. If I go anywhere near the accelerator, I get loud pops that come from the intake area.

I'm all out of ideas and am loosing it with this thing. Any help would be wonderful.

[dnguyen1963]

Loud pops could mean that you might have fuel igniting in areas it should not be. After you shut the car down, take apart the intake boot and check for the presence of fuel (smell?).

[Downeaster1]

Loud pops could mean that you might have fuel igniting in areas it should not be. After you shut the car down, take apart the intake boot and check for the presence of fuel (smell?).

I'll do that first thing in the morning. Thanks for the input!