Fuel pump question for any Mercedes V8 guys

[Mk1a]

03 CLK55 AMG with an m113 v8

Has anybody ever rebuilt a fuel pump for a Mercedes of this era? The sending unit and fuel pump are both part of the same assembly - I think - so I'm wondering if anyone has ever replaced the individual pumps within the unit vs buying an entirely new assembly? ($1300+ from the dealer, still around $1k from a reliable 3rd party seller)

Car cranks but won't start. Crankshaft position sensor (CPS) was replaced in April (with a Bosch part from a good vendor) after getting crank-no-start one evening, though in that case it did eventually start up.

Battery was replaced in July (was 5 years old).

This is an early production 03 CLK55 with the fuel pump assembly under a panel in the backseat on the driver's side. I'm seeing some folks had success replacing those pumps themselves after removing and disassembling the whole package.

Talking about part # 2034703494

Electricals are not my strength - colossal understatement. Having said that, I checked the relevant fuse and it looked okay, checked the fuel relay with a multimeter and it looked okay. But again - not my strength, and if I'm spectacularly off base it wouldn't be the first time. Sending unit seems to be fine as the fuel level is still being accurately reported.

Looks like I'm headed to my local shop this week. Just wondered if it rang any bells for anyone.

Thanks!

 

[Ken Ford]

03 CLK55 AMG with an m113 v8

Has anybody ever rebuilt a fuel pump for a Mercedes of this era? The sending unit and fuel pump are both part of the same assembly - I think - so I'm wondering if anyone has ever replaced the individual pumps within the unit vs buying an entirely new assembly? ($1300+ from the dealer, still around $1k from a reliable 3rd party seller)

Car cranks but won't start. Crankshaft position sensor (CPS) was replaced in April (with a Bosch part from a good vendor) after getting crank-no-start one evening, though in that case it did eventually start up.

Battery was replaced in July (was 5 years old).

This is an early production 03 CLK55 with the fuel pump assembly under a panel in the backseat on the driver's side. I'm seeing some folks had success replacing those pumps themselves after removing and disassembling the whole package.

Talking about part # 2034703494

Electricals are not my strength - colossal understatement. Having said that, I checked the relevant fuse and it looked okay, checked the fuel relay with a multimeter and it looked okay. But again - not my strength, and if I'm spectacularly off base it wouldn't be the first time. Sending unit seems to be fine as the fuel level is still being accurately reported.

Looks like I'm headed to my local shop this week. Just wondered if it rang any bells for anyone.

Thanks!

Assuming it’s like most of the worlds in tank fuel pumps it shouldn’t be that hard. Thinking MB may be one of the few I haven’t had the pleasure.

 

[CAMSDADDY]

Is it getting power at the pump? There could be a fuel pump driver module or could not be getting signal from ECM

 

[Mk1a]

Is it getting power at the pump? There could be a fuel pump driver module or could not be getting signal from ECM

Good question.

 

[SpeedyR]

Is there a way to check the fuel pressure from the pump? That might narrow it down.

 

[Mk1a]

Is there a way to check the fuel pressure from the pump? That might narrow it down.

I know I can check it at the rail on the engine - if I had a gauge, that is - but the pump definitely isn't powering on. Trying right now to check the pins to see if the pump is getting power at all.

 

[Mk1a]

Success! For now, anyway (knock on wood!). I removed the cover in the backseat that holds the fuel pump to check if it was getting power. In the end I unplugged/replugged the fuel pump power and fiddled with it as a last ditch effort before calling for a tow - and it worked! Started right up and ran like a top, and has restarted every time since (one last check to avoid a jinx - yes, still good!)

Thanks to all who replied.

 

[whitmo]

I'd clean those contacts and check for damaged wires at that spot. It would suck to hit a pothole and the fuel pump shut off and leave you stranded somewhere

 

[Mk1a]

I'd clean those contacts and check for damaged wires at that spot. It would suck to hit a pothole and the fuel pump shut off and leave you stranded somewhere

For sure. Good advice.