idle struggling at start-up- MAF?

[rrb986]

When starting the car after it's been parked for an hour or so, the engine struggles to maintain normal idling rpm. Engine stalls if I don't step on the throttle to rev it a little. After a few seconds of revving, engine returns to normal idle. No hiccups after, even when i restart engine immediately after this or when I start it in the morning cold. It seems to occur when car is fairly warm. Any thoughts folks? I suspect the MAF- no CELS though, and car drives normally aside from this odd behavior.

[Brucelee]

We normally recommend the cheap ideas first.

Dirty air filter, dirty fuel.

I recommend a can of Techron first as this has worked for me several times with symptoms like yours. And also pull the air filter and check that too.

After that, the MAF or the O2 sensors seem to be frequently the culprits.

Are you getting a code of any kind? If not, the dirty fuel may be the deal.

[deliriousga]

What Brucelee said and:

Look around for any cuts or loose air system hoses.
Make sure your oil cap is not cracked and is tight and the dipstick is seated all the way in and not allowing air in.

Vacuum leaks can cause the same symptoms and be a pain to find sometimes.

Hope it goes well.

[rrb986]

Let's see- new air filter, fairly new fuel filter- replaced January. No codes of any kind. Will check MAF, O2s and the hoses for leaks. Will keep you guys posted. thanks!

[Brucelee]

Run some techron injector cleaner through there also. Can't hurt, might help!

Good luck!

[spine911]

Originally Posted by rrb986

Let's see- new air filter, fairly new fuel filter- replaced January. No codes of any kind. Will check MAF, O2s and the hoses for leaks. Will keep you guys posted. thanks!

Id personally start by cleaning your Idle Control Valve(ICV). ICVs can start going bad without throwing any code whatsoever-initial symptoms would be extremely unsteady idle. Often times, Emmision control devices such as the MAF,O2s, Vacuum Leaks would throw in a CEL/code. Try locating the ICV, disconnect, clean the connectors using an Electrical Cleaner or WD40. Run a search for "ICV Cleaning" online and im sure itll give you a general idea on how your clean the ICV. ICV failures are fairly common amongst other high end euro cars such as MB, BMWs...BTW, a MAF failure would often be accompanied by stalling, extreme engine hesitation, etc aside from Idle roughness.