Fuel pump help needed

The Best of Mercedes & AMG
Was compelled to replace both sides on mine last year -what with the now-necessary retrofitting of AMG’s superseded hardware- to the tune of ~$1000.
At least its external filter swap is an easy 15-minute/$50 task. ;)
Found scant little debris on its intake screen during forensic investigation. It did keep wayward refinery/filling station rust, macadam and bird droppings from the impellers, though.
The trusty DVM proved its internal armature wiring had failed.

Did you use the lubricating paste that was called out in the WIS document? That stuff lists for $89.00
Not sure if I should even bother messing with it now.Will test/dismantle the pump when I get a chance.
So you had to convert to the C55 pump and filter integrated into the sender?
I was looking at my spreadsheet and the car ran 3597 gallons of fuel through the pump until it's demise, and 1495 of it was E85.
Was compelled to replace both sides on mine last year -what with the now-necessary retrofitting of AMG’s superseded hardware- to the tune of ~$1000.
At least its external filter swap is an easy 15-minute/$50 task.
It is perplexing why johnand’s pump failed so soon. Although both of ours had traversed similar mileage before giving up the ghost, mine undoubtedly pressurized substantially more fuel to the injectors -given its ~18-mpg lifetime average- and been subjected to escalated on/off city drive cycles by virtue its typical operational dictates and age. Note California’s CARB-mandated gasoline blend also ostensibly contains up to 10% ethyl alcohol per LCFS edict.
Found scant little debris on its intake screen during forensic investigation. It did keep wayward refinery/filling station rust, macadam and bird droppings from the impellers, though.
The trusty DVM proved its internal armature wiring had failed.

Just drove the car this morning, and am dumbfounded how much better it runs. I have been plagued by a hesitation problem for months now, and the idle has gotten a tad rough at times to. The hesitation is now completely gone, and the idle is butter smooth. In fact, the idle is so smooth now, I have to do a double take, as I keep thinking the engine died.
I did completely clean the MAF, air duct, TB, and filter box, and put new filters in, so that could be part of it. But, I am very pleased with the outcome regardless of how I got it.
Now, just have to reschedule my body shop appointment and get that taken care of. Just don't want to give the car up, since I just got it back

Did you use the lubricating paste that was called out in the WIS document? That stuff lists for $89.00
Not sure if I should even bother messing with it now.Will test/dismantle the pump when I get a chance.
So you had to convert to the C55 pump and filter integrated into the sender?
I was looking at my spreadsheet and the car ran 3597 gallons of fuel through the pump until it's demise, and 1495 of it was E85.
Was compelled to replace both sides owing to age and a revised 5-pin harness incompatibly. Silly 203 470 34 94 pump has a MSRP of $1300.
It’s quite effective, though, as it’ll empty a full tank when subjected to ~100 miles of track day frivolities.
Still utilizes an inexpensive Mahle-Knecht external filter.

Was compelled to replace both sides owing to age and a revised 5-pin harness incompatibly. Silly 203 470 34 94 pump has a MSRP of $1300.
It’s quite effective, though, as it’ll empty a full tank when subjected to ~100 miles of track day frivolities.
Still utilizes an inexpensive Mahle-Knecht external filter.
Splinter, were you coming from a four pin to a five pin change? What is the extra wire. The four pins are the hot and ground and then the two resistance/sending wires of the float level.
Still haven't done my redo of my fuel pump do to moving duties, but may try tonight.
Ed
Splinter, were you coming from a four pin to a five pin change? What is the extra wire. The four pins are the hot and ground and then the two resistance/sending wires of the float level.
Still haven't done my redo of my fuel pump do to moving duties, but may try tonight.
Ed
legend:
X36/3 connector
M3 pump
B4/1 LH fuel level sensor
B4/2 RH fuel level sensor

Good luck with yours.

https://mbworld.org/forums/attachmen...-fuel-pump.pdf
Here are the two part numbers:
203-470-23-94
203-470-35-94



Great minds............!