fuel relay puzzle ?

[mr rosher]

hi everyone, i would like to ask some questions and for some help if you can please,
today i wanted to depressurise the fuel system on my 93 e280 to carry out some checks on the fuel rail, i removed the big black relay near the battery and the fuel pump still ran, removed the small green one beside it with the 30 amp fuse and pump stopped, now as im having problems with low idle and cutting out on idle after say 40 secs from start up this got me thinking so i removed the cover from the fuel pump and found two fuel pumps, so are both pumps run by one relay and if so whats the big one for, or is each pump run by there own relay,

if you put in the big black relay on its own turn the key theirs nothing, so may be this is my problem,

also i would like to ask you all, when the bonnet is open and you turn the key to on but not running, should the throttle body make a buzzing sound and then it sort of clicks as if a flap is opened then closed again,

last one, can anyone tell me the voltage readings on the air mass plug, im getting 12 volts on pin 4 / earth on pins 1 - 2 / and nothing on pin 5,

if anyone can help i would be very grateful,

thanks rod,

 

[mr rosher]

hi everyone, i would like to ask some questions and for some help if you can please,
today i wanted to depressurise the fuel system on my 93 e280 to carry out some checks on the fuel rail, i removed the big black relay near the battery and the fuel pump still ran, removed the small green one beside it with the 30 amp fuse and pump stopped, now as im having problems with low idle and cutting out on idle after say 40 secs from start up this got me thinking so i removed the cover from the fuel pump and found two fuel pumps, so are both pumps run by one relay and if so whats the big one for, or is each pump run by there own relay,

if you put in the big black relay on its own turn the key theirs nothing, so may be this is my problem,

also i would like to ask you all, when the bonnet is open and you turn the key to on but not running, should the throttle body make a buzzing sound and then it sort of clicks as if a flap is opened then closed again,

last one, can anyone tell me the voltage readings on the air mass plug, im getting 12 volts on pin 4 / earth on pins 1 - 2 / and nothing on pin 5,

if anyone can help i would be very grateful,

thanks rod,

would,nt let be post both pics at once,

 

[roofless]

i think the tall black relay is for the abs if you remove it and start the car the abs light will stay on

 

[mr rosher]

i think the tall black relay is for the abs if you remove it and start the car the abs light will stay on

thanks roofless i will try this and see what happens, i`ve been on e bay tonight and searched for fuel relays for the e280 and it comes up with both the green one and the black one,

 

[C220GJS]

http://www.detali.ru/cat/oem_mb2.as...GM=717.440&CT=F&cat=44Q&SID=54&SGR=040&SGN=03
Going by this list which applies to your car item110 is for aircon compressor and kickdown cutoff, item99 is the fuel pump relay(the green one).

 

[killingtime88]

Mr Rosher where are you location wise ,if you are within range of wolverhampton you are welcome to come and compare what you are getting compared to mine i have a 1995 e280 estate, you seem to have been having problems for a while its about time they were sorted and you started enjoying your ride
Regards Paul