2003 Z4 wont start

[ssargeulb]

My 2003 Z4 won't start. It ran fine until I parked it one evening and then it just wouldn't start. I could not hear the fuel pump when I turned the key so I checked the fuses and decided that the problem had to be the fuel pump. I replaced it but apparently it was not the problem.
Now when I turn the key on I can hear a humming under the hood which I assume has something to do with the fuel pump trying to do it's thing but instead of humming for a few seconds (as I became accustomed to) it runs continuously. I gave it a quick shot of starting fluid and it fired but did not keep running.
I am at a loss as to what to look for or try next. Any thoughts, comments or suggestions would be appreciated.

 

[Roundozo]

Battery? If you've got a voltage reader, hook it up to the battery. I think it should be around 12 or something sitting and 13 and above when running. I know those figures are a guess but someone will be along soon with the correct figures!

BMW's tend to suffer badly with low batteries, you get all sorts of "strange" behaviour.

 

[simonlpearce]

Cam or crank position sensor would be my guess.

 

[Mister T]

I'd also say battery.

 

[Ewazix]

Pointless doing anything until you know your battery is good and is charging.

The basic DIY test with a volt meter involves measuring over the battery +/- terminals without the engine running looking for about 12.4 ish Volts (good battery). Then with the engine running and electrical accessories OFF a healthy alternator should be giving around 13.7v - 14.5v. Stick a load of accessories on then see if the voltage drops below 13V, if so the alternator is functioning but marginal and may be on it's way out.

 

[Roundozo]

Pointless doing anything until you know your battery is good and is charging.

The basic DIY test with a volt meter involves measuring over the battery +/- terminals without the engine running looking for about 12.4 ish Volts (good battery). Then with the engine running and electrical accessories OFF a healthy alternator should be giving around 13.7v - 14.5v. Stick a load of accessories on then see if the voltage drops below 13V, if so the alternator is functioning but marginal and may be on it's way out.

^See, I told you someone would come along with the correct figures!! What a fantastic forum we have!

 

[Mike6]

Obvious thing first - you do have petrol in the car

 

[rjsimmons]

Obvious thing first - you do have petrol in the car

:slaphead:

 

[no fit state]

Does it turn over?

 

[ssargeulb]

Battery checks out and yes, I had fuel.

Allow me to elaborate, it may help...

When I parked it I realized that I hadn't pulled in as far as I wanted so I went to restart it (immediately) however it cranked and cranked without starting. For what it's worth, previous to this the car had always fired up immediately. I did not continue to try figuring that I would look into it later.
2 hours later I turned the key and it fired up as usual and I drove it approximately 30 miles before parking it again. The next day I tried to start it and again it only cranked.

At this point I have the following facts:
- fuel pump is good (just replaced it because I thought that was the problem (apparently not the problem).
- a humming can be heard under the hood which I believe is the fuel system trying to draw fuel / It is now a continuous hum whereas it use to only last a couple of seconds
- the engine fires immediately with minimal starting fluid but stops as soon as the fluid is fired.

I appreciate all that are trying to help, hopefully this will help you help me.

 

[srhutch]

Are you sure the ignition lights are coming on when it won't start?

I had this issue where it would just crank. Turned out to be the ignition switch (not barrel/key)

If your ignition light are on it won't be this though.

 

[fixit man]

Well it seems to be fuel related... as it starts when you put starting fluid in, can you do a fault code read out to get some clue ? I would be thinking fuel pump , but you said that's OK !
Maybe a blocked fuel filter or see this :- http://www.bimmerfest.com/forums/showthread.php?t=316608

 

[no fit state]

Check the EWS unit out. It's part of the immobiliser system and it will let your car turn over but not let fuel in engine.

I had similar problem a few weeks ago after a flat battery. The car would turn over but not start, then I'd try again a few minutes later and it would fire. Then later that day it wouldn't fire again.

Turned out the EWS unit was having trouble recognising my key after the flat battery and so would not let the car start and was throwing the code 2f44.

 

[owm]

This might be worth a read:
http://www.z4-forum.com/forum/viewtopic.php?t=29908

I would say it is good to hook up an OBD2 scanner and try to see if there are any stored codes to help in the diagnosis.