Hi I'm new to owning a Nissan skyline. I recently bought a R33 GTSt skyline from a friend for cheap. The reason being that after about 20 mins of running the engine starts miss-firing and loses some power. still drivable but annoying none the less. My friend had told me he's taken it to his family mechanic and he couldn't work it out. Would anyone on here know of or had a similar problem with their skyline? If so could you please direct me in the right direction? Thanks