325es fuel pump question

[JeLani]

I have a bad fuel pump now , causing bad accelaration and power loss . I called the autobahn wrecking yard in san diego , and the guy asked me if my pump was internal or external. Me: not sure. Is mine internal or external?
Note: i have a 2.7strker and an i head so my search criteria may vary.

[Reichart12]

Both! Or at least you should have two.

[101]

^^^ correct. On a 1986 car, the standard is two pumps. There is an in-tank "transfer pump", and an external high pressure pump.

It's probably worth a peek under the car to make sure that you have the external high pressure pump (it mounts above the fuel filter) before making a call on this. Your tank / pumps could have been changed to the later model standard (which has a single in-tank high pressure pump) somewhere along the way.

[JeLani]

^^^ correct. On a 1986 car, the standard is two pumps. There is an in-tank "transfer pump", and an external high pressure pump.

It's probably worth a peek under the car to make sure that you have the external high pressure pump (it mounts above the fuel filter) before making a call on this. Your tank / pumps could have been changed to the later model standard (which has a single in-tank high pressure pump) somewhere along the way.

I did find an external one which looks like any other fuel pump. It looks old ¯\_(ツ)_/¯ , how do i take a look at the in-tank one since i have gas in it? And which one do i change according to my problem?
My car trips while revving in nuetral , followed by white smoke.. This has happened since the last time i drove the car in which it really didnt like me driving it and shut off

[101]

To access the internal pump, you have to remove the rear seat bottom cushion. There is an access plate that covers the pump / sending unit assembly under the passenger side.

You would have to run the recommended fuel pressure and volume checks in the Bentley manual to determine which pump is causing the issue.

If the issue is fuel pressure related, it could be the external pump or the fuel pressure regulator. If it's fuel volume related, both pups would have to be checked to determine which one isn't up to the job.