Help me please. I have a R33 and for a while i was having trouble with it spluttering and idleing bad mainly after putting it under load. So i changed the coil packs that made no difference so i decided to change the fuel filter. When i took the filter off i tipped the fuel out and it was filthy and brown. So i put a bottle on the line and turned the reds on to see what it was like coming from the tank and it was clean. After changing the fuel filter and cleaning the AFM the car ran fine untill today. I boosted it up it made a pop when i backed off it started to splutter and idle bad when trying to drive it it just wanted to come on to boost and kept fluttering ( i have a bov atmosphere/plumbback) i pulled over to check it then everything went back to normal its now driving fine again and boosting smoothly.
The car is pretty much stock apart from exhaust, FMIC and BOV
Any ideas???