First time poster---

I need some help here - this is the first time I've had to change the battery in my 328 and after doing so it just cranks and cranks but won't start. Dealer said bring it in, right after I explained IT WON'T START. Anyway, anyone have any ideas what may be wrong? I replaced the battery because it died - had Autozone check it - definitely dead.

Also, I don't remember seeing a vent hose when I took the old one out - do I need one?

Thanks in advance for help!

I certainly hope this isn't the problem, but is there any possibility that you installed the battery backwards? You'd have to work at it to get the terminals on the posts, but it can be done. I don't know what negative effects that would have on the car's electrical system, but it can't be good.

I am a new poster, but give me a little credit here. No - it's not in backwards - the terminals lined up easily and all the electrical systems that I can see evidence of (lights, radio, etc) seem to be working fine. Turns over fine - it's just acting like it's getting no gas or something.

I saw a post here on another related issue that said maybe there was fuel in the spark plugs and to remove/clean the plugs and then cranks the engine for several seconds with the fuel pump fuse out. Could this be an issue? I don't know how that wold happen, but I'm getting desperate at this point for answers.

Car was fine before all this I take it. If so then one of a couple of things, not getting fuel, no spark, ECU toasted.
Could also be an issue with the safety relay if the car was bumped. The one in the trunk. You can turn the key to the run position and you should hear the fuel pump if you take the back seat out and put your ear close to the lid. If that sounds like it is running then spark needs to be checked. I think you can pull the valve cover off and use an old spark plug grounded to see if there is any spark.
You are not throwing any codes since you never got it restarted.
Did you do anything else to the car? Even if it is not related it might be...

The car had been fine up unti lthe battery died. The only thing strange that had happened was about a week before the batt died my wife was driving it and said it just cut off while she was driving down the road and slowing to a stoplight. She doesn't drive it too often, and she doesn't drive a stick, so I figured she had just stalled it somehow - it didn't happen again so I didn't think much of it.

Either way looks like my spark plugs are the next thing to check. Never changed plugs in a bimmer, and I've been looking for an excuse to by the Bentley book - guess this is it.

I am a new poster, but give me a little credit here. No - it's not in backwards - the terminals lined up easily and all the electrical systems that I can see evidence of (lights, radio, etc) seem to be working fine. Turns over fine - it's just acting like it's getting no gas or something.

Check fuses. DO you hear the fuel pump starting up?

Do this first:
Pull the coil wire, place it near a ground on the valvecover or engine block and crank it to check for spark.. THEN check spark the same way with one of the plugs.


Fuel pump and it's relay.
Quickie check method:
Crank engine for ten seconds. Turn off key.
Carefully remove the fuel line that runs to the cold start injector and watch for fuel to spray out. Be careful of the eyeballs here. :confused If there's pressure there, the fuel pump is at least running. It also needs the correct pressure, but usually if there's some pressure and spark to the plugs, it'll run.

I had checked all the fuses and I could hear the fuel pump (I used to have Volkswagons with lots of electrical/fuel pumps issues), so I knew that wasn't it.

This story has a happy, if not mysterious, ending though. Problem started on a Friday - I searched forums, talked to my car-knowing neighbor, tried everything suggested except taking out the plugs. So, my neighbor is coming over Sunday night to help me take em out, and I'm thinking 'How late is Barnes and Nobles open on Sunday' to go get the Bentley manual - but I try to start it once more just for the hell of it - and it started!

I had tried pulling the fuel pump fuse and cranking it several times over the weekend to try and clear things out, and it sat in a 110 degree garage for two days, so I'm thinking there was fuel/water somewhere it shouldn't have been that finally evap'ed off. This is purely a slightly educated guess though and it could have been completely unrelated.

Special thanks to HansundFranz for his fuel pump cycle tip in another post, and to everyone who posted with help - I appreciate it!