makecopies

03, 110k miles
Everytime I drive the car like for example to the store. When I come back out to start it up. It starts up fine then the RPM's drop really low and car is about to shut off I have to tap the gas to stop it from shutting off.

Seems like its misfiring at idle too

I was thinking it could be the spark plugs looking at the service history I don't see that it was ever done.

AJCaron12

If it's never had a tune up then it needs one. Is your check engine light on?

jerseystyle

iTrader: (22)

+1 I would start there. Do a COMPLETE service first. If it still does it then you can trouble shoot from there.

Also, this should probably be in the tech forum

makecopies

No Check engine light. Does any one know how much the dealer charges for a tune up?

Let me change that.........on a scale of 1 to 10 how difficult is it to change the spark plugs.

I have done it on a BMW before but they are alot easier to get to.

terrasmak

iTrader: (8)

Mine has been doing that for 80k miles now. The only thing that improved it is the tune from Cobb. I think its actually from the popcharger or intake plenum, don't really care, it only does it when the car is hot. Mine is also an 03

makecopies

Mine just has the Stillen intake. I guess I'm gonna try cleaning the intake and changing the plugs this weekend. I hope that is the fix. It's starting to get annoying.

zakmartin

These are the types of things you need to mention when you ask for help diagnosing problems with your car. Also, how long has this been a problem - since you bought the car or only recently?

Is the Stillen filter oiled? Excess oil on the filter can get sucked down the intake tube and damage the Mass Air Flow Sensor or Throttle Position Sensor, though if that were the case, you'd probably be throwing a code.

You might have crap in your throttle body that's gumming up the butterfly valve, which would explain why your fast idle isn't working properly. Go to your local auto mart and buy a spray can of throttle cleaner/lubricant and clean out the throttle as directed.

As for the spark plugs, yeah, it's probably time to replace them, especially since you don't know the car's full service history. My grandfather used to say, "When you buy a used car, you're buying someone else's problem." This is more or less what he was talking about.

To change the plugs, follow the how-to on this site, go one plug at a time (don't unplug everything all at once or you might get the wires crossed.) Use the right tools and the specified torques. Assuming you don't know much about engines, find a friend who does and have them give you a hand. Stick with OEM parts unless you know what effect aftermarket parts have on the car's performance (i.e., platinum vs. iridium plugs, etc.) On a scale of 1 to 10, spark plugs are about a 2, but it's easy to f-up a 2 if you don't know what you're doing, so if you're still unsure, get a mechanic to do it; it'll be a lot cheaper in the long run.

winger492

iTrader: (7)

The same thing was happening to mine about 2 months ago. It would sometimes crank but not turn over. We checked the fuel pump and the pressure was off. So i swapped it out for a Walbro. We then realized it wasn't that when the car would still not turn on. I had a Nissan certified mechanic look it over and turns out one of the fuses from the IPDM was fried. Unfortunately you cant just buy a fuse, you need to buy the whole IPDM which is about $500. Luckily for me, the mechanic had a few other fuses from other Z's and was able to give me all new fuses for $40. Solved the problem immediately. Hope this helps!

NewJoyZ

Vaccum leak coincides with the symptoms your having. BUT if it drives normally when you first start it up, than that would be rare. Try doing an ECU reset and idle learning procedures. Directions on how to can be searched for or found within Motordyne Engineerings "Plenum Spacer Install Manual" on their website.

seiran

iTrader: (1)

mine did the same thing.. did the idle learning procedure and seemed to have helped... another thing is that i let the car properly warm up.. start it and let it run for a few minutes prior to heading out.. if I don't do that - i could drive 50 feet, put it in neutral and it'll sometimes cut out..

mine has ALWAYS idled super low in comparison to other cars - i think it's just a z33 thing...