Hard start on 2001 BMW 525i

01-525it Every morning when I try to start, the engine would turn over but not idle.. and died. After 2 or 3 tries, and press the gas pedal, it starts. The first 10-20 seconds, the idle is a little rough, then it runs smooth, and works fine. When I restarted the car later (4-5 hours), it is fine, but next morning, it happens again.

I changed air filter, checked battery (12.7 V), fuel pump fuses. There is a half tank gas. Added a bottle HEET (gas line antifreeze). Went to a garage, replaced fuel filter, checked engine fuel pressure (good), Scanned computer, there is no codes indicate anything wrong. What can I do now?

Any HELP will be appreciated!

Asked by for the 2001 BMW 525i
Sorry I don't have a specific answer for you but you could try the following: Leave the car a the repair shop overnight with a fuel gauge connected to the system. In the morning before starting the car check the engine data sensors with a scan tool to make sure everything looks OK. Also note fuel pressure before starting and while the problems is occurring. Anything that is found to be out of spec should be corrected. The shop should also check their online service information for any BMW service bulletins related to the issue.
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Hi. I am having the same problem like yours. Can you kindly tell me if you were able to solve the problem already and how? Would appreciate it. Thanks
Sorry, it was 16 months ago. I don't realy know how it was solved.

Check my records, I changed the fuel filter on May 12, 2009, and the problem was still there after that, so I posted the question here. One day about 3 weeks later, my battery was totally died, I had to jump started the engine, and running engine couple hours trying to charge the battery, but the alternator didn't do the job. A repair shop diagnosed that the alternatir was died and replaced it. Since then, I haven't have problem starting engine.

It ssems like the alternator has something to do with this problem, but I am not sure.
The reason for the starting issues may have been a weak battery due to a failing alternator. If the voltage in the electrical system is too low while the engine is cranking (due to a weak battery) all kinds of strange problems can occur.