That was my reaction after my Z started to run like complete garbage. A little background.. I own a 2003 Nissan 350Z enthusiast 6spd. Have had it for a couple years now and up until recently my car has been fantastic. But now, it goes through these.. modes, like it's bipolar or something.

It will start up nicely most of the time, but soon after it will snap into this mood where it's not firing on all cylinders or something. It will be running great "vroom vroom" and *snap* it sounds like "put put put put" and the idle is really rough. It will snap in and out of this.

From day 1, I thought fuel injectors. But i've taken it to two places now and neither of them could figure it out.

From what I gathered on forums/ the internet, I'm assuming it could be:
-ignition coils
-fuel injectors
- ??

I'm right around 125,000 miles and I just want to get her running smoothly all the time without these little hiccups. Any help would be awesome!

 

What about maf sensor? My car ran fine for a while and then started to get this weird engine reving and it was kind of sluggish driving. Turned out to be a dirty maf sensor. You can go to autoparts store near you get maf sensor cleaner from crc. Take out sensors and spray them good let dry for an hour or two and then resinstall. Did this and my car runs amazing now. They say to clean the sensor everytime you get new airfilters.

 

ah new info. to me. Thanks, I'll check the sensors out. Thanks for the advise!

 

If you do this, be very careful with the maf, its fragile and expensive to replace.

 

do you think it could be anything other than the 3 mentioned options?

-MAF
-Injectors
-Coils

 

if you do this make sure you don't spray end that connects to wires in the car. That should not be sprayed. Just spray the part of the sensor that hangs down into the air intake. Make sure you do about 15 1-2 second spays. Oh don't start the car until it drys off. You will short the sensor.

 

Have you changed spark plugs. Probably be a good idea to do this if you haven't yet with 125k mileage.

 

the plugs are a couple months old... could be that.

More info: When it snaps into this weird mode, I can smell either fuel or oil burning. One guy I took it to said oil was leaking onto my sparkplugs?

Thanks for all the feedback so far

 

Does it run like crap after it's been sitting a while? If you have a slow oil leak, the buildup will cause it to run crappy till the oil clears out.

 

I've never had an oil leak. At least, not to the point that it reaches the ground. I look every day, but no puddles under my car. I'm gonna try this CRC MAF cleaner and see if that makes a difference

 

Yeah, I just realized you said it happens while you are driving. The oil issue would be right when you start it up.

Could be a clogged fuel filter.

 

^yup, fuel filter.... was just about to say that. 125k miles. Might be a good cheap thing to pull and replace.

 

Do these 3, that everyone has suggested.... since all are cheap also

clean MAF
new fuel filter
double check spark plugs since it has recently been changed

reading your first post fuel filter was first on my list, but it looks like everyone has you on track, wanted to post so i can sub to see what fixed it

 

+1 for fuel filter. That would explain the *occasional* choke.

 

I am having exact symptoms. Well about 2 months ago I was. Happened probably once a week. Hasn't happened since but I did catch a video of the possessed thing in action for reference


similar?

 

now i know what to replace around 100k, hope u guys fix the problem

 

That sounds horrible. Id lose my nuts if my car did that. Did you solve it?

 

nope, to this day i don't know what it was. hasn't happened in 1 1/2 months or so.. not sure.

 

You cannot replace the fuel filter - it is permanent. Assume no SES light or codes being thrown? Could also be the throttle body but all we can do here is guess.

 

Thanks for all that guys, I am throwing a P0300 code- multiple misfire or something like that. It flashes on and off when I'm driving it, but it just stays on when it runs smooth.

Can the fuel filter really not be replaced?

It was almost like that video, not to that bad of a point though. That clicking happens though... I'll clean the plugs and maf sensor over the weekend. I'll also see about swapping the fuel filter, if that's possible.

Thanks again, guys!

EDIT: after a little research, the fuel filter is in the fuel pump. so if **** hits the fan in the filter, you have to replace the whole pump. bummer. Any suggestions?