Jimboy1289

Hello,

I have a 09 535i xdrive. It has 120,000mi. It will start and drive normal all day. When I drive for about 20mins then try hard acceleration, the car stalls off then gives fuel pump malfunction indicator. If I unhook the negative cable and reattach, the car will run normally.

Car has brand new fuel pump and filter.

Booyaazaa

Have you pull the codes? it sounds like you replaced the 2 buckets in the gas tank recently. Have you also had your HPFP checked? It is a common failure point in the N54 engine if you have an older hpfp.

hthbd

Hello,

I am having the same kind of issues with my '10 535i E61. At some point when I am driving, the engine stalls. (It happened to me in the middle of the motorway...)'
Impossible to start the engine for 15 to 20 min, then it starts again and run "normally"

High pressure fuel pump and low pressure fuel pump have already been changed but the problem keeps coming over and over.

Did you manage to identify the root cause of your problem ?

Thanks,

scottalexander

Here's my guess.

The fuel pump relay controller is getting hot.

Once it cools down the car will run.

hthbd

Hi !

Thanks. Unfortunately, on my car, this relay has already been changed (same time that the low pressure fuel pump).

scottalexander

You say the relay has been changed.

However, it could still be malfunctioning.

In the past, people that have had similar problems to you have touched the relay controller and have noticed it was unusually hot.

While that's not a scientific diagnostic, it could be helpful.