Sl320 engine cuts off after 30mins

depends on what you mean by "warmed up". If you mean engine reaches normal working temprature and works normally then cuts out , but restarts wwithin 5 minutes and then carries on working normally until it cuts out again, and then restarts withing minutes...have the throttle position sensor checked. It may be that you have a warning code on the dash?
It might be the pedal position sensor alternatively.
If your engine works ok until fully warmed up this may be the problem.
If there are any symptoms before the cut out happens can you please add the details and repost thwe query

well it sounds like a fuel problem i would check my fuel pressure first now if a code came up find out what it means and address it and make sure you have fuel in the tank

Check/replace the fuel filter

this happens on my partners a class but only when the fuel gauge drops to 1/4 full.Now we keep it filled up with no problems.We had the fuel filters replaced without success.I think maybe there are fuel sensors which are telling the car it is out of fuel.Like yourself we would wait for a while then the car would start.

Hi Nichelle, Take the vehicle for a diagnostic scan. If the engine sounds smooth and is running well, I do not believe you need an new engine. What is more likely is a defective fuel pump or fuel regulator. A very common fault on Nissans is the mass air flow sensor, which sounds as if it is the problem with your vehicle. Regards John

There has to be a loose connection somewhere. Being pulled apart under hard acceleration. Do you have any OBDII codes stored? This will lead you to your fault. Hope this helps...

I remember the "Parts Replace" routine all too well from my truck. It's probably the fuel filter needing to be changed, clogging up and clogging the flow.

I would try the crankshaft sensor. About the only thing left in the electrical department. These are known to heat up and fail. Also could be a weak fuel pump, but not as likely as you say it restarts immediately. You should have the fuel pressure checked before replacing it, as it's pretty expensive. ~ $175. I had one that would die intermittently, then it wouldn't restart until you got under the back and kicked the gas tank.

Put a crank sensor on it to fix.

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.