I don't know if this is normal but when i start my car in the mornings the rmp jumps up and down from 1,200 - 1,600 for like 20 seconds then after it drops down to 1,000 so is normal for the rpms to jump around like that? You can actual hear the rpm revs a little for that 20 seconds. Thanks alot

 

There is a good thread on Throttle Body cleaning in the DIY section that talks about rough starts.

May be a vacuum hose leak, may be your O2 sensors or some other stuff.


It would help if you let folks know the year and model of your car and what mods you have.

 

sorry the year model is an 2008 all stock

 

Perfectly normal. Nothing to worry about.

 

That is perfectly normal what you're describing. The VVEL revs high for a bit, then drops and continues to drop as the car warms up. I've researched this issue because I got freaked when I realized it, but all our cars have it. Even the 370Z. Simply put, it's normal. Listen to some exhaust vids with a cold start, and you'll see that all cars do it.

 

yes, that's pretty normal...
but I've heard ppl say that u shud wait for the rpm to drop to normal as the car warms up before u start driving... myth or fact?

 

I don't know if it's a myth or not but I wait a good minute before starting to drive. Longer in winter.

 

The RMP normally should goto 1000-1200 when you first start the car and then should drop to 650+/-50 rpm.

Have ever got Fuel System Tune-Up performed if not you may want to.

I have used following on my 2003, 2005, 2007 cars and they run perfect - try this product made by 3M - I found it's really great.

3M™ Do-It-Yourself Fuel System Tune-Up Kit, 08963

Shop 3M: 3M Do-It-Yourself Fuel System Tune-Up Kit, 08963

Good Luck

 

thanks very much for everyones help, i get it now