Help! check engine light alwasy come up in cold

[2JZDU]

dear all,
I just bought a 93 tt supra which has a very weird problem.

Every time I want start the car in a cold morning, the check engine light will come up, the max RPM I can only rev up to 2000rpm then it will go straight down to idle even I am holding the accelerate pedal, felt like car couldn't suck in any air, also petrol smell will become very stronge,
the radiator fan will work even the car was just started.

At first I was trying to ignore it, but car has no power at all, and it does unbelievable shake if I drive it.

however, if the sun comes out, these will all go away.
I have took it to a garage to get a diagnostic code, but they told me car is all good, has no problem, This almost drives me crazy.

can somebody tell me what wrong is it?
I am very appreciated.