Oshkoshbigjosh

So my fuel pump is causing a long crank but eventually starts after about 2-4 cranks. A few months back, my fuel pump was starting to not work and would give a false reading on the fuel gauge. I bought a sender unit and that fixed my false reading but not the failure to start with less than half a tank of gas. My mechanic removed my fuel pump and found out that the smaller auxiliary pump was no longer functioning and so my fuel pump could only pump fuel from the top of the tank and then it would stop working after it my tank was about 1/4 full. My mechanic worked around it because the car is my daily. He ended up drilling a hole through the bottom of my fuel pump so that it could suck up the fuel from the bottom. It works as it now bypasses the smaller auxiliary pump which is supposed to help the primary pump suck the gas at the bottom.

I am just sick of sitting in my car cranking it 4 times to start. It's embarrassing honestly but the most important thing for me is the fact that at some point this could probably cause damage to my starter over time aside from the pump failing.

I searched for a replacement pump on FCPeuro and pelican parts and I am seeing two different setups for the C32 specifically. The one on FCP is Mercedes Fuel Pump Assembly - Genuine Mercedes 2034703794
which is exactly what is in my car but the price is bonkers. I already have a new sender unit, all I need is the primary pump and the second auxiliary pump. The primary pump on this one has what looks like a pump within the assembly. After researching, I found out that the pumps are Pierburg pumps with primary pump part number is 7.28461.00 but I can't find an exact number for the smaller one attached the primary without pulling mine out.

The main pump on my car also has a part number: 2034700694 and this houses the pierburg pump 7.28461.00

I asked about the individual pumps over a year ago on mbworld and a person replied with the part numbers for the pierburg pumps which are:
For C32
Pierburg fuel pump

Feeder: 7.21088.62.0

Main: 7.22013.02

You can see the main pump is different than what is on my car (7.28461.00) so my assumption is that these other two numbers are updated part numbers.

The one on pelican parts is a remanufactured part that appears to be the primary pump without the pierburg pump in the assembly. The part number is 203470239480and is cross listed to fit pretty much all other w203's including the C55 amg and Clk55 amg.

So here is where it goes even further, after reading countless threads, I find out that many people are mentioning the fuel pump flow rates are different between the C32 amg and the fuel pump flow rates on the C320. THEN I read from other members that the flow rates are the same so that means the fuel pumps are the same or can be switched. The fuel pump on the C320 looks different from that of the C32 but it looks like the one that Pelican Parts has listed.

Even more confusing, within those same threads I read through, I read that the Clk55 pump is the same one in the C32 but which clk55? the w208 or the w209?

Like many of you savvy members, I don't want to replace the entire tank for $2000+ excluding labor like mercedes benz recommends. I also don't want to pay FCPeuro $839 for the fuel pump assembly that inlcudes a sender unit that I already bought new and is already installed in my 32.

I want to buy the primary pump and the secondary auxiliary/feeder pump because that is all I need BUT i can't find them. All I can find is the smaller pierburg pumps or the one on pelican parts that does not have a smaller pump attached to the side or a pump inside it.

So, my biggest question, has the fuel pump been updated and is a direct replacement on the C32? Will the connectors be different? The C32 has a 4-pin connector and some of the other pumps have a 5-pin connector. If I solder the 4-pin connector to a 5-pin connector fuel pump, will it work?

It seems like everyone that has asked a question about fuel pumps for the C32 have left out multiple important details that would be useful for the other owners. I just want answers because if I can use the fuel pump that is listed on pelican parts, that would be HUGE. Total game changer and it would negate the need to buy such an expensive oem fuel pump system and would also negate the need to fit aftermarket pumps like the Walbro 255lp lh whatever, or the GS333, the Kemso pump which all need to be retro fitted. Everyone that has used a Walbro pump or aftermarket pump has left out the details needed to confidently replicate the process. After reading so many threads, I am just more and more confused.

so, HAS THE FUEL PUMP BEEN UPDATED FOR THE C32 AMG?




Yeah I'm crazy...

Oshkoshbigjosh

It's ok y'all can reply with information when you want. In the mean time, I will be doing my own detective work to find a solution to the C32's fuel pump woes without paying 900 doll hairs. If I can't...well I'll let future me figure that out.

So far, I've been talking to the pelican parts specialist and have learned that the fuel pump (203470239480) is not for the C32 and they have pulled the part from the C32 amg part line up. I'm quoting directly from their email reply:

"Thank you for the VIN. Unfortunately it does not appear the the pump you reference would be correct for the C32. I have pulled the correct part number and have put t quote together for you to review here:

https://www.pelicanparts.com/cgi-bin...command=lookup "

So for now, we can eliminate it as a possible option. I will continue looking for now

I also contacted FCP and they could only supply a diagram for part numbers of the entire fuel system. This should help any owners who need part numbers for something other than the pumps.

Oshkoshbigjosh

Another update

There is a pump service on eBay where the seller is offering their service to rebuild it for you. I was thinking of just paying for it to get it over with but since its almost 600 I decided to message them. They told me all they were doing was replacing the pumps sooo...how much are the pumps and how much of the labor is he charging? I have no clue. He asked about my symptoms and I told him it had a long crank and he said it wasn't fuel pump related and that I should bring it to him and have him check it out for 4-6 hours. I'm going to give him the benefit of the doubt that he truly wants to help diagnose the issue and not charge extra for looking it over. I think it's a good alternative if you want to just pay and get it over with.

BUT, I have no clue how much they would charge per hour or diagnose it. My mechanic is reliable and told me its the pump without a doubt. He really looked into my car (spent almost 3 hours testing everything) and I was there with him while he removed the pump and everything.

Also, I'm on a mission to do this myself or at least acquire the parts to have my mechanic do it for less than any other option out there.

Here is the link to the fuel pump service for the 02-04 C32 amg. I am in no way affiliated with this individual. In fact, I think it's a bit of a ripoff. I would rather put the extra 300 and get it NEW from FCPeuro with a lifetime warranty. But if you're local like me, this could be a last resort or try to work with the guy on bringing down the price because it is a bit too high in my opinion

https://www.ebay.com/itm/Fuel-Pump-M...i:223181071838

My next step is to track down these pumps and order them from the right places. If anyone has a clue on where to get authentic pierburg pumps, let me know.

I'll be back

Oshkoshbigjosh

I ended up buying both pumps individually for less than $200 on eBay after searching for hours on eBay, Amazon, ebay.de, ebay.au, google, etc.



The part numbers I used were:



Feeder: 7.21088.62.0



Main: 7.22013.02



I used these numbers to source the parts because even though I bashed on previous forum members not being thorough with their posts when changing the pumps, a majority of them provided these same part numbers consistently throughout the years on many threads. So I am crossing my fingers that the pumps I ordered are not only authentic but the exact same part. I was so close to buying from german auto parts store on eBay or from some Australian parts store but in the end, I paid a little extra and ordered from 2 different sellers in the US.



If you are having a hard time finding the pumps, try removing the periods in the part numbers and you should have different results. One of the pumps was for the e39 BMW and that deterred me for a while but it looks exactly like what is in my car so I think it'll fit.



I think I did ok at finding a good price on them. One was 76 doll hairs and the other was 90 doll hairs. ECS tuning was one of the sellers and they were the cheapest option I could find that was in the US. Tedious and time consuming to figure this all out but it's probably because I overcomplicated it. I am too cautious when it comes to buying parts but if it works out for me, you don't have to take the time to do it because I already did all the research for you. Unless you are obsessed with double checking for your self, then I don't blame you.



The next update should be receiving the pumps, examining them, comparing them, disassembly of the fuel pump system, replacing them with the new ones, and a test drive.



I know this is a long read, but I know this will be helpful information for other current owners when their fuel systems begin to fail because it will. I wonder if this thread will be used in 10-20 years when these are classics and are sought after. Time will tell...

Oshkoshbigjosh

An unfortunate delay in fixing my fuel pump issue:

So i finally received the pumps that I ordered from ebay. The secondary auxiliary pump was all good. I questioned its authenticity because it has TI Automotive on it instead of Pierburg but after some research I found out that Pierburg was bought out by TI Automotive and they are still selling quality parts and are still manufactured in Poland like Pierburg originally did. I hope that is true. Here is what I received:









So this one looks identical to the one currently on my car. This pump was about 76 doll hairs on ebay and it arrived fairly quickly.

Then the one from ECS Tuning arrived. I was so excited because thanks to Covid 19, I no longer had to drive to school so I was finally able to take my car apart and figure this out. I opened the box and there lied the blue Pierburg box. It was in poor condition. All taped up and despite there being packaging paper, it sat at the bottom where it could absorb the most damage from poor handling. Maybe the guys/girls who prepare items for shipment overlooked this one or they just don't care. I opened the pierburg box and immediately closed it. I was furious. I paid close to 100 doll hairs for the wrong item. The picture in the listing was what I was looking for. Instead, I get this part which I'm not even sure I can remove bits to access just the pump. I contacted ECS and they haven't accepted my return despite them saying they would. I'm on limited money so I can't just buy another pump in the meantime until something of mine sells to recoup the money lost. I know about Jalopnik deep-diving into the history behind ECS but I never thought I'd be a victim to their poor service.

Here's what I received from ECS Tuning:






That's the first and last time I will ever trust ECS tuning. I'm just waiting for their return label. I'm even going to send that sticker back. They probably sent the wrong sticker too.

Oh well I'll get back to you all when I've got everything I need to do the job.

Oshkoshbigjosh

An interesting find that I came across when looking for the main pump. Bosch could be an alternative for the pierburg pump using the part number 0986580129



I found this picture of a bosch pump that actually has TI Automotive engraved in the metal BUT it also has 7.22013.02 engraved on it too. Could this be a Pierburg part but manufactured for Bosch?



Here is the photo of the one I just purchased! I'm taking the risk to get to the bottom of this! I can not find this part number anywhere in the forums so maybe I'm the first to find this ? I hope not

Oshkoshbigjosh

I've had the "Bosch" pump since Wednesday but unfortunately, my family's other car broke down so I have to fix that one before I put my 32 under the knife so we have at least one form of transportation. For now, I just want to show the part. This is quite an interesting find considering the stock system is still 900 dollars in 2020. I also want to include another potential part number from Delphi. I found this Delphi pump that appears to be a TI Automotive (Pierburg) pump as well. The part number is 16141183176 and I've only seen a few eBay listings where the TI Automotive engraving is visible.

Because IT Automotive bought out Pierburg and since Pierburg was a OE supplier for multiple makes, you can find a few other brands that I haven't mentioned that also appear to have the same engravings from the Pierburg pump and the Bosch one I currently have. It is a bit riskier with those because there aren't pictures up close showing the product you're getting. I would suggest sticking with know names like Pierburg and Bosch but Delphi is a known supplier for MB so it could be an alternative which is why I am mentioning it.

Some of the brands that look like they're using TI automotive pumps are Beck/Arnley 16146752368, 16141183176, 16146752368 which is an MB parts supplier, and Meyle 3149190018 (Might not be a TI Automotive pump but they are a reputable MB parts supplier), and JP Group 0004701794 which is a brand I've never heard of but the listings I came across seem to show a TI Automotive pump with the proper engravings.

I am mentioning all of this because maybe the part number you are using is giving you no results or the results are not what you are looking for. Just be sure to contact the seller to see if they can provide a photo of the item or at least give you a guarantee. I know these findings are insignificant but it could broaden the potential to DIY solutions.

Below are photos of the Bosch pump I received with clear engravings that the pump isn't really a bosch pump. They simply added a sticker. Looks good to me

liquidusculade

So what did you eventually figure out? I like how thorough you are with figuring this out, but like most threads, it seems to be incomplete.