Mechanics

CRANKS BUT WON'T START

1981 Mercedes Benz 300sd

Engine Mechanical problem
1981 Mercedes Benz 300sd 4 cyl Two Wheel Drive Automatic 200000 miles

I purged the lined with the plunger, no effect. I have noticed that if a disconnect the fuel line in, rifgt at the plastic fuel pre-filter, no fuel is pumped. I do not hear the fuel pump with the key on or when the car cranks. Shoud I hear it? Fuel does seem to pump out of the injector pump though. I suspect the fuel pump. Am I missing anything?
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Hippsakamo
August 22, 2009.



It does sound like the fuel pump is weak or bad. Here is a how to for checking it. Check it out and let me know what you find.

http://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

Thanks, where is the fuel pump? CHILTON SAYS IT IS IN LINE, under the left pass floor panal, but I DON'T see it there. Is it in the fuel tank? In line next to the fuel tank?

Tiny
Hippsakamo
Aug 23, 2009.
I just tried liiking I up with our online repair manual and the info isn't available. I believe the Chilton manual is correct. I don't think it's in the tank on your model.