Hello sirs.

I have been ridden my 75' 280z from 2013.

When I finished my college from US, I came back to Korea with my Z.

I had never thought about this problem because in US I have done most of needed job for 280z by myself. however In Korea I have to let the mechanics do the job for my Z.

So, one of them ask me whether the rhythmical up and down sound of L28 original engine of 280z normal or not. Now I think it could be the problem that the engine fluctuating like harley davison sound.

is it normal for 280z? or its not? if it is not, what would be the problem? I have changed AAR for this problem but nothing have changed.

Additionally, I had used intellitronix RPM gauge(red color) for few years, it worked perfect. but when I changed it to same product but different colored one(white), the RPM shows in the tach fluctuating like crazy. why is that so?

Sorry for my english skill and I hope you guys can help on this problems.

Thank you.