Hello I’ve got a 300 zx for my first car😂😂 I know right probably not a good idea. But anyways I’ve done a lot of work to it and it has taught me a lot about cars. It has 85,000 miles and it seems to have problems starting when cold and sometimes even when it’s warm out. I have replace fuel filter put new fuel injector in that we knew was bad and two new batteries and I have tried to run heat through thinking there was water in my gas tank but that does not seem to be the case any information would help thank you