Miss.fire after changed a fuel pump. Please help

[Tommy2]

[Bought a 325 ci 2001 that was parked for 2 years from neighbor. They changed a fuel pump and I didnt know was 2 pumps then. I drained bad gas from tank. Filled premium gas after removed bad gas and now it's misfiring in multiple cylinders. Any suggestions

[MIKYZZ4]

Test fuel pressure at fuel rail.

[Tommy2]

Hi thanks for ur ..respond .I know that my car has two fuel pumps if I unplug the one from behind the driver side .it does not change anything...why or how do I know how to test it ..please help

[MIKYZZ4]

YouTube is your source for instruction , here:https://www.youtube.com/results?sear...BMW+FUEL+PRESS

[MarcoZandrini]

The car has as one fuel pump. It’s located under the rear seat cushion, behind the panel in the right side of the car. Did you change the fuel filter? The fuel filter contains the fuel pressure regulator. The only brands of fuel filter to buy are Mahle and Keyser. The fuel filter is under the car, under the drivers seat, inboard of the frame rail, behind a metal panel. Buy 6” of high pressure fuel hose and 6 stainless steel clamps as the hoses and clamps at the filter are old.

[MIKYZZ4]

Technically the vehicle has one fuel pump.
Tommy, you are referring to the Left fuel level sensor/sucking jet pump,
pictured in the diagram here:https://www.realoem.com/bmw/enUS/sho...diagId=16_0373

- - - Updated - - -

As i suggested earlier, test for adequate fuel pressure at the fuel rail Schrader valve,
as shown in the UTUBE vids.

[MIKYZZ4]

Now that you verified the vehicle starts and is salvageable,
I would add some Techron fuel system/fuel injector cleaner to the fuel,
Run that out-Then replace plugs with a new set of NGK sparkplugs.

You must find the source or cause of the misfires, perform what was recommended so far as easy,cheap first steps.

[marcva]

Fuel filler. Eyeball the spark plugs to see they are ok. Look for leaks in the air intake...squeeze the runner tubing to look for cracks or gaps. Smoke test if needed.

[jclausen]

You have one fuel pump one sid of the tank has the fuel pump and the fuel level sender the other side has only the fuel level sender and as mentioned above the jet pump that brings fuel from the non pump side checnage the fuel filter and what are the fault codes