330i Stalling as I pull away at lights???

Hi guys, I drive a 2001 330i and recently (past 3 months) it has been stalling as I pull away from the lights, it dosen't do it all the time, and it seems the revs drop very low just as I put my foot down on the accelerator and it will either stall or hiccup (not sure if that describes it properly). I put a new battery in, thinking that was the problem but it still happens.
I took it to a local garage and he drove it and it was fine, he said sometimes they have to be driven hard and fast. I tried this but it continues to stall.
I'm thinking it could be either a blockage in the fuel distribution maybe? or something along those lines, I am not a mechanic and dont know my way around cars, but that seems the logical choice.
Does anyone have any experience with this sort of thing, or have any ideas before I start throwing more money at the problem!
Thanks in advance.
btw its an automatic and has done @45k miles

try using the search function on the forum, youll probably find something quick, seems like a few people have this problem

Is it worse (or only) when the motor is at full operating temperature? Failing cam shaft position sensors is a possibility.

It happens when i drive it cold, but maybe yes it is worse when the engine is hot. To be honest I only drive it 9 miles or so twice a day, four or 5 times a week.

Originally Posted by tturedraider

Failing cam shaft position sensors is a possibility.

+1

The intake camshaft position sensor causes symptoms like that when it fails. Car will run fine and act up sporadically.

Of course there are other possibilities. Mine failed at 125k miles. 325xi

Ok i'll give it a shot. How big a job is it for a complete novice to do? and where should I go to get the parts? or should I just take it to a local BMW specialist?
Ive seen a few posts where people replace the outlet sensor too, is this worth doing at the same time?
Thanks for your help!

Originally Posted by Dotty

Ok i'll give it a shot. How big a job is it for a complete novice to do? and where should I go to get the parts? or should I just take it to a local BMW specialist?
Ive seen a few posts where people replace the outlet sensor too, is this worth doing at the same time?
Thanks for your help!

The job is pretty straightforward. The hardest part, which is not "hard," is accessing the connector on the end of the sensor, which has a ~30cm wire. Just a minute, I'm going to fetch some photos...

There are several good DIY articles on replacing the intake CPS. Just search here or at e46fanatics.

Many parts houses carry this component: ecstuning.com, getbmwparts.com, autohausaz.com, etc. See the "sponsors" of this site for more.

Start by going to realoem.com, which is a BMW parts listing. This site is absolutely required!

In addition to the intake CPS, you'll need a CPS o-ring -- about $1USD. Also, get an o-ring for the VANOS solenoid, also about $1USD.

To get to the plug, which is under the intake manifold, you'll have to remove the air intake box. This is not hard but since you've never done it before, you'll have a bit of an adventure. Search this site for excellent DIY articles on how-to do this.

Have you "read" the codes that your engine has certainly "thrown?" The "Check Engine" light may be illuminated, in which case codes have been stored. The code will certainly point to the CPS if this really is the root of the problem. Auto parts stores will often read these for you. You should probably buy something there to show your appreciation.

The parts should be around $130, on this side of the Atlantic anyway.

Let us know how things go or if you have further questions. And do search and read the many good DIY articles here.

Good luck!

PS. Don't be tempted to buy the cheap aftermarket sensor. Get the genuine BMW version. For the exhaust CPS: don't bother until it throws a code. The exhaust CPS isn't as critical as the intake. Saying all that, I replaced my exhaust CPS AND the crankshaft position sensor while they were still functional (at 130k miles).

Thanks for the reply! I went out and gott a code reader to double check and I'm getting two codes, the first is P0344 which is the CPS and the second is P0365 which is the exhaust sensor i think?
Tomorrow I will get both sensors from the local BMW dealership and a couple of 'o' rings, hopefully with all the information on here I will be able to do a respectable job.
I will update you with the results when I'm done.

Bought both sensors and a couple of 'O' rings for £198, I didnt feel confident and didn't have all the tools so I took it down to the local BMW specialist and had them install it for me for £104.
My car runs excellent now, and the fault codes are no more.
Thank you all for your help, I'll be recommending this website to all the people I know who drive BMW's

Originally Posted by Dotty

Bought both sensors and a couple of 'O' rings for £198, I didnt feel confident and didn't have all the tools so I took it down to the local BMW specialist and had them install it for me for £104.
My car runs excellent now, and the fault codes are no more.
Thank you all for your help, I'll be recommending this website to all the people I know who drive BMW's

Glad to hear this fixed your problem.

Thanks for updating us.