1987 420 sel fuel pump problems

[Rose]

Hi everyone,

I love my 420 it's just I am having problems with fuel pumps, I have replace them, the fuel filter, fuel relay and invested a good $600. but It still won't start, I can't even hear the fuel pumps when I start the ignation. :-? Anyone else have this problem? I have tried looking for a service manual but they are next to impossible to find. Can anyone help

Lost and In Love with my car :razz:
rose

 

[Myros]

manuals

Rose , you can get CD and hard copy manuals from e-bay, and from Mercedes directly, at a cost. Someone here may have a similar model and be able to help. Give us a few more details, such as year of manufacture, engine and chassis nos, and see what we can unearth.

In the meantime, you could have a go at the link below.It will give you an idea of what can be had, although when I tried to order from one from my local MB, their computer couldn't do a thing with the part number, despite it being genuine MB in origin.


http://wwwsg.daimlerchrysler.com/Projects/wi/channel/files/772.htm.

 

[Rose]

Thanks for the info

Rose , you can get CD and hard copy manuals from e-bay, and from Mercedes directly, at a cost. Someone here may have a similar model and be able to help. Give us a few more details, such as year of manufacture, engine and chassis nos, and see what we can unearth.

In the meantime, you could have a go at the link below.It will give you an idea of what can be had, although when I tried to order from one from my local MB, their computer couldn't do a thing with the part number, despite it being genuine MB in origin.


http://wwwsg.daimlerchrysler.com/Projects/wi/channel/files/772.htm.

I have started a search for my manual with no luck, if you could help this is the info on my car: 1987 420 sel Mecedes Benz, 126 chasis, automatic transmission. My mechanic wiht 30 yrs. of experience in MB is working on it, but I would like to know some of the background of my car. We have replaced the fuel filter, the 2 fuel pumps, and the fuel relay switch all new, but we are not getting any electrical juice to start the fuel pumps, the car does crank over it just won't start.

Any ideas? Appreciate any the help

rose

 

[Myros]

it would seem prudent

to check the power feed to the pump. If your new relay is working fine, it should energise the pump while the motor is being cranked. You should be able to feel it humming away as the starter turns. Test lamp, multi-meter and trusty hand required. If no juice to the pump as you say, but juice from the relay ( test the output from that as well), the trouble lies inbetween. At worst, you could run a positve feed from the battery to the pump (carefully) and see if it powers up.

Is there any smell of petrol at all from the exhaust. You could try whipping a plug out to see if you can find evidence of petrol in the combustion chamber.( I don't think you will though, it sounds like feed to the pump is the culprit.)
I take it fuses are ok, worth a twiddle anyway, as they can get a bit corroded in sometimes.
Afraid I can't help much with the actual car, it's not one of the ones I know well, but maybe one of the gang has some insight for you.
Good luck


How good is your German? try this about bosch fuel injection from the german sternzeit site. It might help. I need a dictionary and a lot of time to make head or tail of it.
http://www.sternzeit-107.de/modules.php?name=News&file=article&sid=154&mode=&order=0&thold=0