See my signature for model info - somewhat similar to yours.

It has one pump. From what I've seen in the MB repair doc, a lot of the 103 motors in the 300Es have 2 pumps and maybe the 420/560 V-8s - not sure about the latter.

My fuel pump, accumulator; fuel filter are all located next to one another. If you have 2 pumps, they will be next to one another. I'd bet a buck you have one.

I replaced my entire fuel delivery system at the rear of the car earlier this year. Here are a list of parts you may wish to consider obtaining beforehand should you end up replacing the fuel pump. Chances are they're either original or very old. This is not a tough job, but not one you want to do a second time.

Here's the parts list:

4 fuel hoses changed

Delivery Fuel Hose - 22mm attachment - 126 470 16 75
Return Fuel Hose - 19 mm attachment - 126 470 41 75
Fuel pump To Elbow Hose - 123 476 30 26
Accumuator To Elbow Hose - 126 470 40 75 - 5.5mm - only dealer has it

Fuel Tank Screen - 46mm or 1 13/16" socket will break this loose - part number - 201 470 05 06

Fuel Tank Screen Gasket - 110 997 01 45

Fuel Pump - Pierburg - 7.21659.52 - There's also a Bosch Pump - I Used Peirburg because that what the car came with.

Best to drive car 'til it's as close to empty as you can get it. Even after doing so, you're going to drain 2.5 - 3.0 gallons of gas when you pull the delivery line off the fuel pump. I first pulled grn. strap off battery and laid an old sheet on the ground in the work area to help prevent sparks that might occur should a hand tool get dropped accidentally on the concrete surface. If you create any spark while you're doing this, it will likely be you last DIY job. Easiest to remove the pump, accumulator; filter as a unit. You can do this by removing all required hoses first, then a couple of 8mm nuts that fasten this 3 part assembly to the car. Afterwards you can remove each part individually on a bench.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"