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Car Stalled 1977 280SE - Fuel Pumps?

Started by carzilike, 06 October 2023, 07:17 PM

carzilike

Hi everyone, I took my 1977 280SE for a drive today and after being on the highway for 30 mins or so I noticed the car is struggling for power. I have driven the car a dozen or so times on the highway and never felt this before

The car died as soon as I got off the highway and I couldn't get it to start again. Got towed to nearest MB specialist and they confirmed its the fuel pump.
Should these cars have one or two pumps like the W126? My car has 1 pump and its being held in with zip ties which is not a good sign

Yesterday I used "Marvel Mystery Oil" as fuel injector cleaner and I'm guessing that might be the culprit? I followed the directions on the bottle

When turning the key to position 2 - you hear a very slight noise for a millisecond from the pump trying to initiate. It doesn't sound like the usual noise I am use to hearing. Its very faint

The shop tried whacking the pump as I have heard some people say tapping them / whacking them can sometimes work but that didn't work

I have two options

A) pick up a USED BOSCH pump from a local (1hr away) MB parts hoarder and take it to the shop (1hr away) tomorrow and have them install it with a new Bosch Fuel filter
B) wait for a new BOSCH pump to arrive (1+week as I'm in Canada) from an online retailer - no one stocks these here - not even the MB specialists - OEM pump is about $450+ tax locally from a parts shop and a lot less online

---------- I'm noticing on the parts websites that that different pumps say - Up to 089586 OR From Chassis 089587 ----------
Given that my FIN is below 089586, I only have one option it seems

I wanted to ask if there's anything else I should do before ordering the pump? I could take a used pump over there tomorrow and hope for the best or is that being too hasty?

I am facing a similar issue on my 1990 560SEL and on that car I tried jumping the fuel pump relay to see if there was power going to the pumps

Is there a similar method that I could use to test the pumps? Other than directly attaching a 12v source to the pump itself? You do hear some noise when turning the key to position 2 so the shop said there is power but pump is not initializing when you try to crank

daantjie

Honestly looking at that horror show of a fuel delivery package I would personally replace everything back there.  For sure that does not look like a OE Bosch pump.
That filter looks ancient too, so might have a clogged filter/tank situation going on.
Daniel
1977 450 SEL 6.9 - Astralsilber

revilla

#2
Wait. We're here to help, not to criticize your setup.
To answer your questions, and before you start throwing parts in BLINDLY, yes only 1 pump, not 2. Yes, there's a way to test the pump without starting the engine. But before giving you any advice, I guess you're confortable with basic mechanics, as safety with fuel related components is VERY important.
Test 1:
Remove air filter.
Look at what's under, sort of a spider with lines going to the injectors. That's your fuel distributor. Right next to it is a blue connector towards the inside of your engine bay.
With key in off position, remove that connector. You should hear nothing.
Then put it back in slightly but without locking it in. Turn the key to position 1, where you see all the little lights on but without cranking. Back to engine, pull that blue connector back out. You should hear the pump running as long as the blue connector is disconnected.
If no noise, it could be MANY things, from a simple cable, to the pump relay, etc. The key here, and that's something not everyone is able to do unfortunately, is to understand how the system works first, be able to diagnose in fractions, find the root cause and fix it without throwing darts in the dark as many do. You'll waste time, money, effort then frustration will visit you, and you might abandon your project. Nobody wants that, right?
On the other hand, if you follow the correct diagnosis path and start fixing things up, you'll learn, your car will improve and your pride to own it will grow with that.
Test 2:
Put your transmission lever in R or D.
Crank your engine. It won't crank nor start of course but you should hear your pump running as long as your key is turned to cranking position.  If not, further analysis is needed. We'll help you with that.
One step at a time.
Assuming your pump makes noise, we need to later test for fuel volume and pressure. But that's later. Basics first.
Please keep us posted. We want your car running and getting better.
Robert
W116 1977 280SEL & 1979 280SE
[img width=150 height=100][url="http://revillagodfroy.com/MB%201977%20280%20SEL/album/thumbs/IMG_0371.JPG"]http://revillagodfroy.com/MB%201977%20280%20SEL/album/thumbs/IMG_0371.JPG[/url][/img]

carzilike

Thanks a ton for this response. I forgot to mention the car is a 4spd manual - can I still use the method you described by putting it into 1st gear / R?

The used pump is going to cost me $100 CAD plus 4HRS of driving back and forth to pick it up and drop it off to the shop. The seller is willing to test it on a bench before I purchase it from him but no guarantees.

The only new pump I can find for chassis Up to 089586 is a Bosch unit from FCPeuro which will cost me about $200+ after import duties, shipping, currency conversion (USD TO CAD) etc and it'll take 1 week to arrive and at least its new (Friday)

I'm not in a crazy rush to get it running but I do feel bad its sitting there dead in the shop taking up space

carzilike

Quote from: daantjie on 06 October 2023, 09:02 PMHonestly looking at that horror show of a fuel delivery package I would personally replace everything back there.  For sure that does not look like a OE Bosch pump.
That filter looks ancient too, so might have a clogged filter/tank situation going on.


I do agree with you. I think a used OEM / Bosch pump + a new bosch fuel filter has to be better than what is currently in there now. I guess it was only a matter of time before it quit. What else should I look at replacing? I'm having trouble finding a kit like you get for the W126 cars which comes with hoses, connectors, etc.

carzilike

My car's air filter is off to the left front headlight - so would I remove this whole airbox? The engine bay is a mess of wiring going left and right. Some of it is very questionable..

daantjie

I would replace all the hoses at the fuel delivery package.  These are known trouble spots on these cars and those hoses will be brittle and leak over time, especially if they're original to the car.
The accumulator I would leave if you don't have a hot start problem.  That's a classic tell of a tits up accumulator.  They are pricey unfortunately.
The main feed line out of the tank screws into the in tank strainer.  I would also replace the strainer while you're at it.  They are cheap and readily available.
I know folks don't like the shotgun approach to fixes but in my opinion when it comes to safety and fuel delivery I don't bugger around.
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

#7
"My car's air filter is off to the left front headlight - so would I remove this whole airbox? "

Why?

Re: engine bay

I see a couple of extra red wires - prob one goes to an aftermarket radio?
The vac lines are out of place
The ball chain for the cruise control looks strange.

google" 280se engine" and look at images.
http://img573.imageshack.us/img573/9153/mercedes280seyellow6.jpg
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

johnnyw116

#8
Seeing the pics i noticed that you have an D-Jetronic (so your car must be older as 1977) , and than you need another type fuelpump that gives an lower pressure ,and i also noticed they changed the original D-jetronic pump for an later model pump
 
JohnnyW116

revilla

Hi,
Definitely not a 1977 car as stated  from the start which would have a K-Jetronic injection system. So none of the advice given before applies. I would disconnect fuel intake hose at engine, place a suitable container (or extension hose to a container) and crank and see if fuel comes out. If none, you've got your first answer regarding the pump. If yes, what condition of fuel? Clear? Good amount? About 1 liter every 30 seconds? The answers to those first questions will determine next steps. Definitely, changing filters/hoses would never hurt, but we can't cross fingers that the car will miraculously start running right after that. Neither with tapping the pump with a hammer.
Good luck.
Robert
W116 1977 280SEL & 1979 280SE
[img width=150 height=100][url="http://revillagodfroy.com/MB%201977%20280%20SEL/album/thumbs/IMG_0371.JPG"]http://revillagodfroy.com/MB%201977%20280%20SEL/album/thumbs/IMG_0371.JPG[/url][/img]

revilla

About buying a pump right away.  What if that pump arrives you crank and nothing? Or during installation you realize it was just a loose contact, or rather just a stubborn/tired relay, or other little thing? Just saying.
Robert
W116 1977 280SEL & 1979 280SE
[img width=150 height=100][url="http://revillagodfroy.com/MB%201977%20280%20SEL/album/thumbs/IMG_0371.JPG"]http://revillagodfroy.com/MB%201977%20280%20SEL/album/thumbs/IMG_0371.JPG[/url][/img]

carzilike

https://www.fcpeuro.com/products/mercedes-electric-fuel-pump-280se-0580254975

I am taking a chance as I can always return this item and will only lose the shipping costs.
The shop that its at has told me its the fuel pump for sure so if its not then I will have them diagnose further and I am taking their advice and ordering this part based on that advice... not sure where else to start
As the bill will keep growing if I keep asking them to dig deeper and they are a very busy shop from what I saw

carzilike

Quote from: daantjie on 07 October 2023, 01:19 PMI would replace all the hoses at the fuel delivery package.  These are known trouble spots on these cars and those hoses will be brittle and leak over time, especially if they're original to the car.
The accumulator I would leave if you don't have a hot start problem.  That's a classic tell of a tits up accumulator.  They are pricey unfortunately.
The main feed line out of the tank screws into the in tank strainer.  I would also replace the strainer while you're at it.  They are cheap and readily available.
I know folks don't like the shotgun approach to fixes but in my opinion when it comes to safety and fuel delivery I don't bugger around.

Where can I purchase all the hoses and connectors and clamps etc?
I did not notice a hot start problem and have driven the car in hot weather a few times
Are you able to share a link or part number to the strainer? Would this part # apply to EU spec vehicle also?

carzilike

Quote from: rumb on 07 October 2023, 02:09 PM"My car's air filter is off to the left front headlight - so would I remove this whole airbox? "

Why?

Re: engine bay

I see a couple of extra red wires - prob one goes to an aftermarket radio?
The vac lines are out of place
The ball chain for the cruise control looks strange.

google" 280se engine" and look at images.
http://img573.imageshack.us/img573/9153/mercedes280seyellow6.jpg

Yeah one is going to aftermarket radio
Not sure why Vac lines are out of place - the door locks don't work with the key - I can't even turn the key in the driver door lock when inserted - it feels like the lock cylinder is glued in place on drivers door

the ball and chain is some DIY thing the farmer who owned this did - it must be aftermarket. surprisingly it works

carzilike

Quote from: johnnyw116 on 07 October 2023, 03:06 PMSeeing the pics i noticed that you have an D-Jetronic (so your car must be older as 1977) , and than you need another type fuelpump that gives an lower pressure ,and i also noticed they changed the original D-jetronic pump for an later model pump
 

Can you please share the part number?
I ordered this pump which is for
1977 Mercedes-Benz 280SE Up to #089586 (my cars vin is well below this)

https://www.fcpeuro.com/products/mercedes-electric-fuel-pump-280se-0580254975