When i first start my car up, it will idle at 1000 rpms for about 20-40 seconds then settle down to between 6-800 rpms. Is it supposed to surge like that when you first start it?

 

It will do that a little when it's colder out.

 

Sounds normal. Cars will do that on cold startups.

 

The PCM is programmed to increase the idle speed on cold starts, with a table of RPM vs coolant temp. There should not be a "surge" in the idle speed, just elevated, and slowly come down as the coolant heats up.

Not exactly an "Exhaust" topic

 

All cars do this. I love starting my dads 5.3L when it's cold out. It sounds awesome when it starts up and jumps up to ~1200-1300rpm.

 

That's good to hear. I always thought there was something wrong with my car because it did that.

But on that note, when I'm driving and the engine is already heated up, if I put it in neutral at any speed more than 5 mph, it will idle at about 900 rpms instead of the normal 800 at a stop. Is this something of any concern?

 

Sounds like a vacuum leak somewhere.I'd take the car in and get it checked out.A little hose can cause this I think.my02.

 

This is also normal. It's called 'Throttle Fowler Offset' in the PCM. Purpose is to prevent stalling/stumbling when coming to a stop with no throttle. It varies from +0 to +400 RPM, dependent on speed, the faster you go the higher the TPS%=0 (no throttle) RPM will be.

 

^that's good to hear.

But I think I'll take fatdog's advice and have someone take a look when i get a chance. can never be too picky with cars.

 

"follower"

 

IDK, Fowler sounds kinda neat.

 

my car idles at 2000 till it gets warmed up i dont even have to give it a little rev to get going lol