Help with 190E fuel pump problem
 

I have a 1985 190E that is not starting.

I put in a used fuel pump and the car started and ran for a couple of days.
then it died again. this time though i hear the fuel pump energize when i turn the key to the on position, but when i crank it it does not go on.I have tried starting fluid in the air filter and the car starts and runs until the fluid runs out.
Is thier a secondary circuit that runs the fuel pump after it energizes?
What should i be checking if thier is not a secondary circuit?

Thanks for the help

BIG AL

If you hear it once the key is on then it is still most likely running. Turn the key on and then feel the pump to see if it is still energized. Also you can remove your fuel pump relay and jump two pins to constantly energize the pump to determine if it is the relay. Not sure what two pins though. Another thing to notice is that if the CIS-E controller does not sense the engine running it kills the pump, so it could be a bad crank sensor, or Ignition Controller as well. Do you have spark? Do you have fuel pressure at the Regulator? It could be a clogged fuel filter, bad accumulator, bad regulator! You say it runs til the fluid is gone, so we can guess it has spark and that the coil are working. But what it does not have is either fuel pressure, or crank sensed, or a bad fuel pump relay.....