I took my car into Nissan of Chantilly today because every morning when I start up my 2005 Z it's tough to turn over and the volt meter reads 15.5 - In addition to that, it idles really high until I put it in Reverse or Drive (it's auto unfortunately) and then whenever it goes into drive the RPM's drop to 400 RPM or so. Even when the car is warmed up and I'm sitting at a light, the RPM is constantly fluctuating between 400 and 600. Anyways, so I take it into the dealership today and they hook it up to see if I'm throwing any codes (Check engine light was not on, nor was any other warning light) - They said they couldn't find that the alternator was over-charging and that they're 90% sure that it's my spark plugs - The car still has the original spark plugs that came with it when it was initially sold. So I'm thinking about having one of my brother's technicians (bro is a service manager) to do the work because Nissan quoted me $500 for some F-ing spark plugs. I wanted to see if anyone else ever had the same problem with their Z simply because I feel that Nissan doesn't care about it because they aren't making any money - I have a very good aftermarket warranty with $0 deductible that my brother hooked me up with. Last time I was at this dealership, my MAF went out and the bill came to $978 with towing - and I paid nothing. Also, I know how it goes in the auto service industry hence my brother. Anyways, if anyone thinks this is just the spark plugs, please let me know...and anyone whose ever changed Z spark plugs - how difficult is it? Thanks guys.

 

Changing the plugs sucks... the first time anyway.

 

-diy-spark-plugs-change-huge-pics.

 

A vacuum leak can cause this. You may also try to perform the reset procedure,

http://www.technosquareinc.com/350reset.htm

 

It's not the spark plugs but you should replace them anyways.

 

It's either a vaccum leak or you need to reset the ECU and throttle body. Lol @ it being spark plugs. Typical douche dealership techs. Try the ECU/throttle body reset first. It's the easier thing to do...

 

Might also wanna clean the MAF too, since you lost one already maybe you got some dirt or oil making its way into the intake.

 

+1. The MAF is an easy clean with some electronics cleaning spray found at any Pepboys...

 

Wow...thanks for the help guys. Yeah, but would a vaccuum leak not show up on a diagnostic test? and how is that repaired?

As for the spark plugs, I'm simply going to buy stock plugs and have one of my brother's tech's install them. I've done pretty much everything except for spark plugs. It sounds quite tedious from what I've read thus far. Also, I did the real reset for the ECU by doing the whole thing where you turn the key and stomp on the throttle (with the engine off) and it reset just fine, you could see the check engine light flickering and alll of that mess. I believe someone else mentioned something about a different kind of reset... could you elaborate on that? And I aplogize for the delayed response, my internet was out for a couple of days, just moved into a new development. But yeah, if you guys could elaborate on the other reset option and the vaccuum leak, I would definitely appreciate it. Thanks again.

 

^^ throttle body reset. It puts the throttle body in "learning mode", so it resets your idle...

 

Gummed up deposits on TB butterfly gave me rough idle in past. Cleaned w/spray TB cleaner.