For the past 4 to 5 months, my Z has been acting really strange during a warm start up.

During a cold start up, its start up every single time without fail.
If I try to start up the car within 3-4 hours of it running, it refuses to start 90% of the time.

The engine always turns over. It just isn't getting enough fuel, or its getting too much. After I try to initially start it, I'll let it sit for 1-2 minutes, and then try it again. Its starts up just fine.

What I've done so far:
I bought a walbro fuel pump, in hopes that that would solve the issue. After I installed it, the problem went away for a couple of weeks. Then, steadily it started showing up again. Then it wouldn't start 90% of the time.

Fed up with it, I reinstalled the stock fuel pump with intentions of taking it back to the dealership. I even unhooked the ECU for 4 straight days. It worked well for a couple of days, and now it's doing it again. I will be taking it in on Wednesday.

Does anyone have any ideas or suggestions? I know for sure it's a fuel issue.

-Acree

 

I heard about an issue with intelligent keys causing a problem on the news the otehr day. They mentioned the entire Nissan lineup except the Z. Maybe that could be a problem?

Edit...I found the recall and it isn't the same thing...sorry.

 

Yeah when I was at the dealer the first time, they mentioned other models having those issues. I switched out the key the next day, with the same results. Thanks for the suggestion tho!

-Acree

 

This might be a retarded suggestion, but what about fuel system cleaner... or spark plugs

 

I thought there wasn't a fuel filter in our car? Or are you talking about the liquid cleaners you put in the gas tank?

And as far as the spark plugs, I look into that. If I go pull them out, what should I be looking for?

-Acree

 

I meant the liquid cleaner stuff. You can get a bottle of pure techron (chevron proprietary stuff) at autozone, or something like redline fuel system cleaner.

Spark plugs... the way I understand it is they usually reflect the state that your engine was in right before the motor shut off.

Black - rich
white - lean
light brown - just right

so if you wanted to know what was happening at 4000rpm, you'd have to rev up to 4k rpm and then kill the motor immediately using the key.

I'm not an expert on spark plugs, I've never even changed spark plugs myself yet, so maybe someone more experienced can chime in...