I was sitting in a parking lot today adn my car had been idling for about 3 or 4 minutes when i noticed that my RPMs would drop about 100 every few seconds and along w/ this the car would shake a little bit. I thought it could've been pinging but i'm not too sure. I did hear a very light pop when this happened. I never noticed this before but i've never payed attention either... is this normal? I tried to restart teh car but it still happened..

I accidentally put 87 gas in my car last fill up but since then filled w/ 93 octane. could this be the culprit?

 

You know, when I first got my Z...and when I first started it up in the morning, and waited at the red light in neutral..it wasn't really smooth at a constant RPM, but rather bouncing and kinda rough...i have *no* idea what kind of gas the dealer put in there and i don't know if its supposed to be like this; i doubt it.
any ideas?

 

If the idle varies plus minus 100 RPM I don't see a problem.

 

yeah but varying i can stand but not the vibration along w/ the varying. Ive seen varying idle on friends car by like 500 or 600 and i'd be real worried about that, but this was just a concern. the car was damn sluggish w/ 87 octane gas, sucks for u californians :-p.. i <3 94 octane

 

87 octane???

 

aka unleaded rather than the suggested premium (91 octane)

 

87 octane is the 'regular' in NJ. heh its kinda like a medium cup of soda i got today at checkers. It was 42ounces! (thats almost 4 cans of soda!!!) I wanted like 3 or 4 sips jeesh... they dont have a small option. I was like whoaaa... anway, my premium here is 93 while in cali its 91... comparing wise its bboth premium but my premium is MORE premium..mmmmm i need sleeeep...zzzzz

 

No offense intended, but I'd NEVER use anything less than 91 octane ( which is the max I can get here in AZ) And, if I had 93 octane available, I'd sure as hell spend the xtra couple of bucks per tank for premium. My 2c.

 

rread teh post, it was accidental. i told the dude 93..he put in 87..too late by the time i noticed.

 

Many people have experienced a wandering idle. A smoother idle was one of the major claims of the grounding kits that everyone uses, and I noticed it in my car after installing one. Do you have a grounding kit on your car?

 

I second what kcobean said. While sitting at a stoplight, my idling would vary a little. After installing my grounding kit, my idling is steady.

 

Being a noob that I am, is it really that difficult to install the grounding kit?
I read the howto and to me it seemed like it would take like 4 hours...man but i wish i could put one in

 

This was the VERY first mod I did to my car. Shouldn't take you more than an hour with simple tools. It's quite easy.

 

my car has done the same thing since i bought it, dealer has blamed it on the intake everytime i brought it in. I dont even care anymore, its hot in texas and as long as the a/c is running the car idles smoothly.

 

get the grounding kit

 

Yeah, nothing but premium in my car. It's only like a $2 difference per fill up any ways.

 

I also have the occasional rough idling problem where the motor feels like it's stumbling.

 

My 05 enth has done this from day 1.

It is very noticable while running at idle in a garage because you can hear this knock noise echoing off the garage walls. It knocks every 5 or so seconds. The idle moves about 100 rpm and the car shakes like a mother Fukcre.

I'm only at 1700 miles so it hasn't been serviced. And yes I use 93 octane.

Bottom line - the Z has a million problems and I'm tired of worrying about them. I'm waiting for its first oil change or a warning light to address the problem.

 

how much did you get your car for??

 

This RPM dip is caused by the extra demand put on the engine while the AC compressor is cycling on and off......turn off your AC and it will go away!?!?!?!?