03'55AMG

Originally thought my CPS went bad, but replaced it to no avail. Found no fuel pressure and good fuel pump fuse, so I am in need if a new one! Can anyone help!?

E55Greasemonkey

I will be listing my old fuel pump for sale soon, it's still in the car. I just bought a new one only because I have 100k miles on my car...They are still in good working condition. Looking for $175 shipped. I could have it out as soon as tomorrow night if you are interested. Check the wire connector on your pump..it may be burnt or melted and will also need to be repaired. The pins and connector are available from the dealer.

03'55AMG

If the connector isn't the issue here, then SOLD! I will inspect the connector in a few minutes here. And I will reimburse for expedited shipping.
Correction: I will pay up front for extra shipping, not reimburse. Lol

03'55AMG

The connectors appears fine, but I would like to test them first to be sure. Anybody know how to test with a DVOM?

E55Greasemonkey

You should have 12 volts momentarily once you switch the key on. And try putting a gallon of gas in the tank...Sending you a PM.

03'55AMG

PM replied! Will test connectors here shortly.

PACougar

According to MB the fuel pump is supposed to be replaced at 60K miles if I remember correctly. I would never put a used pump in a car, just doesn't make sense, what happens when a used pump dies in 5K miles. Not to mention a used pump is going to come with a clogged fuel filter, at least to some extent.

E55Greasemonkey

The FILTER is supposed to be replaced at 50K. There is no service interval for the PUMP. They are separate pieces. Fuel pump failure on these cars is very rare, the exception being when the filter is not replaced at 50K, and the pump electrical connectors burn/melt due to increased amperage trying to push through a clogged filter.

A new pump costs over $500.

V8weight

I don't mean to step on anyone's toes, but I have both complete sender's/ pumps/ filters, etc. in Mercedes boxes with less than 100 miles on them. I had the senders replaced under warranty due to "the fuel smell", only to have the smell come back within a week.... I raised enough stink to have the entire tank and both senders replaced immediately after. They gave me the senders back to keep, so if you have any interest in them, shoot me an offer...

03'55AMG

As of right now, I am trying to find an issue here. I tried testing the connectors for voltage and couldn't find any. I put my test leads into the connector ports, put the ignition into the on pos. and repeat until I tried all of the combinations. Nothing. So I checked the fuse and relay again, and swapped both out for new ones. You can hear the relay actuating when you enable the fuel pump in STAR, but nothing at the pump, including voltage. Can someone give me a clue as to where to proceed? I haven't checked the passenger side sending unit yet, but I will soon.

Also V8 weight, I would be interested in your pumps and etc if its the right price. I was going to get a Eurocharged heat exchanger, but I have to figure this out first.

PACougar

The filter is part of the pump assembly, do you have a part number for a replacement filter?

E55Greasemonkey

typo

Alps

As PACougar says, the filters are part of the pump assembly, if you could get hold of the "Teabag" type filters you could replace them, but you cannot get them seperately.

in most cases i think the pumps are overworked due to clogged filters and kill the pumps and melt the plugs.

E55Greasemonkey

The amount of misinformation on this site given out by people who have little or no technical or hands-on experience is mind boggling. I'm done.

Alps

which part are you refferring to?

FACT
- filters are integral to the pump assembly
- they can be removed once pump assembly is taken out and split
- filters are not available seperately
- pump is normally dead at this point so have to replace the lot anyway (even if you could get the filters seperately, which you cant)

PACougar

I'm confused, I'd love to be able to just replace the filter, why wouldn't you want to post up the part number for it so we can all replace them rather than the pumps? I have quite a bit of technical and hands-on experience, you seem to be the one giving out incorrect information. I'd be pleased to be wrong and happy to admit it, please post up the part number.

03'55AMG

Update
With the help of E55Greasemonkey, and Shardul, we have it narrowed down to bad pump/clogged filters. The stock fuse chart is wrong on its location of fuses for certain things, like, the fuel pump. The chart lists it as being on the rear SAM, when in reality it is the 30 amp fuse on the right side of the battery by the spare tire area. After finding the real location of the fuse, I observed it was blown. Either caused by clogged filter of bad pumps. I haven't replaced the fuse yet, but when I do I will find out if it is a blown pump.

Man, these cars are touchy and can be real hard to love at times.. Lol

jarvis210

ok i have all the facts for you. The drivers side sending unit it the filter. The passenger side holds both the fuel pumps(dual pump system), the connector that supplys the fuel pump power on the e55 is on the passenger side. the relay is in the right rear of the trunk. you need to take the right side trunk panel out. mercedes wiring diagrams are not accurate on the picture cause there are 3 different variants but the are all located in the right rear of the trunk. your issue is most likely the fuel pump. i highly suggest replacing both left and right side sending units when you do this repair. if you have any other questions just pm me ill give you all the info you need to fix your car

03'55AMG

I am aware of this now. Correct. I already stated in above posts, that I checked relays and fuses, and also stated MB diagrams were wrong. I also stated this. Read above Already planned on this. Take some more time to read the above posts. Most of this is already stated, and I already have the fuel pumps removed, as well as the trunk apart to check wiring and internal fuses inside spare tire area fuse block.

Worth the wait

I am confused.

I understand you have a very high level of understanding above the vast majority of the members. Given you are an experienced mb tech, I would hope that is the case.

Are you saying that the fuel filters in the W211 can be replaced without replacing the entire assembly?

Where's is the misinformation?

Thanks for any help you can provide.

03'55AMG

Another update. Fuel pumps are def. toast. Have new pumps and sending units coming already, then we'll be smooth sailing! Here's some pics of the old stuff.

In the rear fuse block in the spare tire area, there are hidden internal fuses. Sometimes these blow and can cause symptoms of a bad fuel pump. They are impossible to buy without buying the whole new fuse box, unless you know someone that has some from replacing a fuse box themselves and keeping the good fuses. Thankfully, none of mine were blown.

AgSilver

Rolling on the floor laughing. Will somebody please help me up?