Hey mate, I had the same trouble with my R32 GTR, its actually your air flow meters, try pulling them out and spraying electric cleaner on them that should do the trick. If not then maybe open up the casing because the components may have buckled a bit over time and connected with one another. If you know how to solder you can do it yourself but if not you better get an auto electrician to do it. Dont worry its an easy job, and i can guarentee that they dont need replacing skylines last forever hope that helps mate
