My car is a 1993 Subaru Impreza WRX. ( GC8 )

It has a ej20g engine.

The problem is that my car stalls after running for about 10 seconds.
When i give it some gas it revs okay but after 10 seconds it just dies..

I have been having cold start issues lately. It cranks longer before it starts and sometimes stalls. Second try and it would start perfectly. It was not a big issue. until 1 day it started running weird and surging, i made it home. and ever since it idles for 10 seconds and dies.

I have reset the ecu. There are no engine codes.

I have replaced the IACV. it did not help.

I have replaced the Fuel Filter. also did not help. When my fuel pump primes it creates lots of pressure.
is it possible the fuel pump is losing pressure after 10 seconds of running?

Would the car stall if it sensed a miss-fire?

It seems to miss fire sometimes, other times it idles nicely at 1,500 rpm for 10 seconds and dies instantly.

Thank you for your time, any input is greatly appreciated.

Sincerely,

Kamil Klosowski