engine wont fire

hi my name is Mehmet Kashif i have a 1975 Mercedes 450SL
just recently i had my ECU tested and a New Fuel pump and a New relay the car wont fire
any suggestions?
regards mehmet

Hi Mehmet,

does the fuel pump actually work? When you turn the key before the point of ignition you should be able to hear it. Maybe the new relay is not working. Why was it actually replaced?
Did the engine fire before?

Chris

This all started when i changed the spark plugs i turn the key don't hear the buz before start up so i had the ECU tested its working perfect then changed the fuel pump for a new one still wont fire now i changed the relay which i have changed three times still no buz no fire and the pump don't seem to get any power?
I'm scratching my head over this one

mem

Mehmet, check the small wire at the Batterie. Positive post.
Rudiger

You could try to remove the relay and bridge the right pins on the socket to get power to the pumps. In my case it's pin 8 & 7, but I'm not sure if this is same for your early SL. If the pump is then still not running measre the current at the pump. Maybe you got a broken cable?
Another test would be: screw out one spark plug and see if it is wet, this would indicate that you got at least fuel coming but no ignition. Did you get the right spark plugs?

Checked the wire on the Positive post even clipped it and put on new contacts plus spark plugs are the same as the old ones i changed,
Is there any chance t could be the ignition key itself still no buzz when i turn the key.My relay has only five pins for the pump and when i turn key on pump not buzzing because i can touch it. Have missed any other relay? i even cleaned the relay contact points with contact cleaner?
regards mem