[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 and 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 pelicanparts 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 one 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 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 203470239480 and 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?

am i crazy...?

 

[APowerX]

No you're not crazy. I also dug in this rabbit hole. the cross referenced pump/buckets for the c320 are 3 bar while the oem pump delivers 3,5bar on paper and close to 4 bar irl. The fuel pressure regulator in the filter compensates a bit but it cant work miracles. In one of the 32 FB groups, someone complained his car was always laggy. Then remembered he let a shop replace his pump assembly only to find out they've used the 320 one.
The part numbers for the individual pumps are correct. However there is also another Pierburg pump that is compatible on paper: 7.22013.69.0
Also its the W209 CLK55 that has the same assembly.
Also the more stronger aftermarket fuel pumps, like the high end walbro's burn out the rear sam because of high amp draw. stock pump should draw around 9A max according to Star diag.
If you get around to sourcing the pumps, could you please make a detailed installation post?

 

[Oshkoshbigjosh]

No you're not crazy. I also dug in this rabbit hole. the cross referenced pump/buckets for the c320 are 3 bar while the oem pump delivers 3,5bar on paper and close to 4 bar irl. The fuel pressure regulator in the filter compensates a bit but it cant work miracles. In one of the 32 FB groups, someone complained his car was always laggy. Then remembered he let a shop replace his pump assembly only to find out they've used the 320 one.
The part numbers for the individual pumps are correct. However there is also another Pierburg pump that is compatible on paper: 7.22013.69.0
Also its the W209 CLK55 that has the same assembly.
Also the more stronger aftermarket fuel pumps, like the high end walbro's burn out the rear sam because of high amp draw. stock pump should draw around 9A max according to Star diag.
If you get around to sourcing the pumps, could you please make a detailed installation post?

Thank you for getting back to me! I am determined to get this fuel pump issue sorted out without paying 900 doll hairs. I think it's an absurd tax to charge so much for something that should be 4-500 doll hairs max. I assumed it was the w209 clk55 that had the same assembly but when I search FCP or any other site for fuel pumps under that chassis, the system looks way different from what I have installed or what is the stock pump.

I am weary about buying the pierburg pumps as well because I've read it is a pain to disassemble the primary pump. Also I am worried about the authenticity from some sellers who have them listed for so cheap. Some of the top connectors look different or the sizes are different. Very little is known about how to replace these pumps so if I find a good direction I would follow through with a write-up.

I figured that these walbro pumps would cause some sort of issue so that is my absolute last option that I still would not do. I contacted pelicanparts and their parts specialist confirmed the fuel pump( 203470239480) is not for the c32 and pulled the part out of the C32's parts lineup. I'm quoting directly from the email:

"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:

Pelican Parts - Track Your Order "

So that answers my question if the pump has been updated (it has not been updated) and if the part would work for the c32 (it does not).

I'm repeating myself because I don't want other owners to stumble across this post and feel confused.

The situation where the FB member allowed a shop to do that is what scares me. Fortunately, my mechanic does not source my parts because he knows I do my research.

I will update this post as I learn more

 

[APowerX]

Totally agree it's a f***** ripoff for a part that likely costs a tenth of what they ask in production. Also indeed you have to be wary about chinese knockoffs of the Pierburgs. The main pump is actually very easy to disassemble and replace. The top of the bucket is only held in by some plastic clips that you need to pry back very gently. The only tricky part is swapping the hose on. That should happen very gently with some heat and prying.

https://thefabricatorseries.com/build-blogs//c32-amg-w203-fuel-pump-issue

好背的一天(w203 c32 fuel pump掛點) @ porsche 965 :: 痞客邦 ::
Some very interesting links on the swap. Especially the second link.

I don't think there are other options than replacing the pumps individually. So just new pumps in the old/same bucket.

 

[Oshkoshbigjosh]

Totally agree it's a f***** ripoff for a part that likely costs a tenth of what they ask in production. Also indeed you have to be wary about chinese knockoffs of the Pierburgs. The main pump is actually very easy to disassemble and replace. The top of the bucket is only held in by some plastic clips that you need to pry back very gently. The only tricky part is swapping the hose on. That should happen very gently with some heat and prying.

https://thefabricatorseries.com/build-blogs//c32-amg-w203-fuel-pump-issue

好背的一天(w203 c32 fuel pump掛點) @ porsche 965 :: 痞客邦 ::
Some very interesting links on the swap. Especially the second link.

I don't think there are other options than replacing the pumps individually. So just new pumps in the old/same bucket.

I also can't fathom that there aren't pumps that fit out cars from bosch (they do have a sender unit that is a direct fit). They make a pump for every other benz but not ours.

I have read both of those links before and they super insightful. The fabricator series even bashes the forums a little for not being thorough enough.

I think you're right about replacing the pumps individually. 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 and 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 to 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.

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 too. 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 for me.

Fuel Pump Module SERVICE only fits 02-04 C32 AMG 203 470 34 94 | eBay

Find many great new & used options and get the best deals for Fuel Pump Module SERVICE only fits 02-04 C32 AMG 203 470 34 94 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

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]

I forgot to include the fuel system diagram a helpful customer service employee at FCPeuro sent me. It should help with looking at the entire fuel system without removing it and also tons of part numbers

 

[APowerX]

Congrats on the purchase. I also find it puzzling there are no off the shelf buckets for our cars like the other models. Also the stock system is manufactured by Marwal (never heard of this brand, probably OEM). Forgot to mention i swapped the pumps on mine too. I also included a handy WIS manual specific to the C32. let me know if you need other manuals as i have access to WIS and EPC. Keep us updated.

 

[Oshkoshbigjosh]

Dude thank you so much for that. Seriously thank you. If you were near me I'd buy you a meal from Five Guys. I have never heard of marwal before so that is strange to me. Yeah I feel like the C32 was left alone when bosch decided to manufacture fuel systems for mercedes.

 

[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 an 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:

 

[Oshkoshbigjosh]

More pictures:

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

 

[APowerX]

Sorry to hear about the issues. Yup that pump that ECS sent out is the wrong one. 7.22013.02 was apparantly succeeded by that one but i would NOT use that in my car. And that BOSCH branded pump looks exactly right. I'm confident it's just a rebranded Pierburg pump.

 

[Oshkoshbigjosh]

Sorry to hear about the issues. Yup that pump that ECS sent out is the wrong one. 7.22013.02 was apparantly succeeded by that one but i would NOT use that in my car. And that BOSCH branded pump looks exactly right. I'm confident it's just a rebranded Pierburg pump.

I was seriously bummed out. Have you had any issues with ECS? I didn't even take it out of the bag because I think it would be too much trouble to attempt to remove the connector bits to try to fit it to my own pump.
I think it was meant to happen as it forced me to search for another pump.
I could not believe my eyes when I saw the bosch pump with a TI Automotive engraving. The part number does not pop anywhere in benzworld or mbworld so it could be the first find which I think is important. The pump I bought was 76 dollars including shipping. There was a few others for over 90 on ebay. Using 7.22013.02 with or without periods gets you Pierburg pumps in the US for about 130 dollars or 115 dollars from Europe or AU. The Bosch pumps themselves are more readily available in the US for less but I would advise anyone to contact the seller to confirm that the pump has TI Automotive on it or at least the correct connectors.

Hey APowerX, has this info been somewhat helpful to you even though you're not in the US?

Once I get all the parts and tools ready, I'm going to make a new thread with a quick summary of part numbers, issues,etc. and then the DIY guide.

If it all works out, maybe the mods can sticky it or other members can pull important information from it.

 

[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

Sensitive content, not recommended for those under 18

Show Content

 

[APowerX]

Hey, any updates on this?

 

[Deplore]

Is there any particular reason why you're not able to use a pump from a 55 car? The flow rate for any of the V8's are significantly higher than a V6, even if it has a supercharger and uprated injectors.

W203 C55 is NA I think, and it has to feed 8 injectors that each have higher CC's than your M112k up to 6000 rpm.

W203, W209 55 series use the same pump setup, if I'm not mistaken.

 

[Deplore]

Furthermore, the long cranking points to a failed fuel pressure regulator/check valve, so how are you sure it's the pump?

 

[APowerX]

Is there any particular reason why you're not able to use a pump from a 55 car? The flow rate for any of the V8's are significantly higher than a V6, even if it has a supercharger and uprated injectors.

W203 C55 is NA I think, and it has to feed 8 injectors that each have higher CC's than your M112k up to 6000 rpm.

W203, W209 55 series use the same pump setup, if I'm not mistaken.

I think you're mistaken. M113k and M112k share the same injector 400CC versus 280CC of the C55.
Also C55 has a different setup. CLK55 has the same dual pump bucket.
E55 in tank system is also different.

 

[Deplore]

Shows how much experience I have with M112k.

What about the pump themselves? They should be the same, even if the housing is different.