Engine Cutting Out

[JPCR33]

hey I’ve had my r33 SII gtst manual for 2 months now got it with a major service etc however if the car has been left outside in the heat when I go to turn it on it will run then suddenly the revs will drop and car shuts down. but if I rev it a bit and move the car a bit and when the temp gauge goes a bit up the revs won’t drop....this is a weird issue and dunno what to do or what’s wrong

but if cars left in garage it will turn on normally and I continue driving normally and engine doesn’t shut down

any help will be greatly appreciated

thanks Jason