Help new car not starting

[Lanny]

Hi! I hope somebody can help. I have just bought a 1992 280E. I previously owned a 220E and both have an identical intermittant problem. When I go to start the car the fuel pump does not seem to kick in. However when I attatch a battery booster pack it starts first time. I have now replaced the battery and the problem is still there. All terminals appear clean and once the car starts it is faultless. I put up with the first car doing this however the second car seems worse. Any ideas.
Lanny

 

[mattkh]

When I go to start the car the fuel pump does not seem to kick in.Any ideas.Lanny

Hi
Do you normally hear the fuel pump kick in. If you hear a sort of a buzz, how long does it last ?

 

[Dieselman]

Fuel pump relay, ignition switch, OVP in that order.

 

[Lanny]

If the fuel pump kicks in then the car starts first time no problem. Other times I turn the ignition to position two the fuel pump does not start. The car has never cut out.

 

[jaymanek]

in that case i would suggest the ignition switch..

 

[Lanny]

Thanks for all the replies so far, in dieselmans reply OVP was mentioned, excuse my lack of knowledge what is this?

 

[Dieselman]

OverVoltageProtection relay. It guards against the battery being connected the wrong way round. They can suffer from dry solder joints, but I doubt it's that.

When the car won't run check the voltage to the pump from the relay and ignition switch.