I have been having problems with my car starting. It only does it every now and then, but it's been doing it more since the weather has been getting colder. It just turns over and doesn't start until I give it some gas. When it does start it runs really rough like it is gonna shut off again. Once it is warmed up and has been on the road it is fine, but it upsets me that it does this. It has 108K on it, I only run premium gas in it, and I never let it go below a quarter tank. I have had it to daniels bmw twice now to figure out what is going on. The first time they told me it was the spark plugs and they have since been replaced. The second time they said all of their computer tests were fine and they suggested I replace the air and fuel filters. So I did, but it doesn't seem to be making a difference. They told me the only way they will be able to figure out whats wrong is when I have to tow it to them. I really don't wanna do that. What is going on? If anyone has any insight as to what might be wrong, please let me know. I absolutely love my car and want to get it fixed.

I'm betting it's your idle air control valve (IAC). It's a little stepper motor that controls the idle speed. Probably gummed up and sticking. They'll want to replace it, but search around here, you can pull it out and clean it with carb cleaner spray. Free fix, give it a shot.

Hrm +1 on the ICV...grab some intake cleaner and a tooth brush and give it a clean. Do a search on that, there's a few extensive threads on how to do it. See if that helps.

If not, it may be a fuel system or ignition system problem. Kind of hard to say definitively over the internet. :)

If you can, try to post a video of it.

Any "check engine" lights when this happens??

My Idle Control Valve was going bad but it would throw a CEL. Actually the car ran pretty well and still threw the CEL.

I also changed out my plug wires with Magnecors...but don't see how that could be related to a warm up problem.

Mass Air flow sensor wire is another easy clean item. You need the CRC Mass Air Flow sensor spray cleaner (Pep Boys) or get the CRC Electrical contact cleaner at Lowes/HD. Spray the thin wire inside the MAF...just don't touch it !

ps: check all of your hoses. Secondary air pump has some small plastic hoses running down to the air pump on drivers side. The one that looks "corrugated" about 1/2" diameter falls apart