Measuring

Hello! I'm new to the forum and I am having a problem with my s13.

The car has been running great for a few months and is now acting up on me to the point where I can't really use the car

I was out driving about a month and a half ago. Doing some drifting, everything was going great, engine running perfectly until suddently after a U turn drift, the car started to feel like it wasn't getting enough fuel. The tank was fairly low on gas so I figured the fuel in the tank had just flown up on the side wall of the tank therefore not supplying the pump with fuel. The engine started running almost normally again after about 15-20 seconds so I drove back home in second gear, slightly struggling. I took it to the gas station the next day and it felt just fine. Filled it up and drove back and it started acting up once again. Giving it too much throttle causes it to cut out. It doesn't happen at a specific rpm so I don't think it's limp mode?
It almost sounds as if the car runs on 3 cylinders once it starts acting up. Letting go of the throttle slightly makes it go away until you throttle once again. I reach about 0-0.1 bar of boost before it happens. The engine never cuts out when you stand still and rev it. Runs fine.

The engine also barely runs until it warms up when it's cold outside. I've never driven the car in cold climate before and I have to constantly pump the throttle in order to keep it running for about 3 minutes before it idles by itself. Don't know if these issues are connected or not though.

The engine in question is a forged ca18det running a stage 3 chip. Boost sits at 1 bar.
I've tried the following things
- Replaced all the coil packs
- Replaced the sparkplugs
- Replaced the MAF (z32)

Hopefully someone has an idea of what might be causing this.
Thanks in advance!