All Mercedes-Benz carbureted engines use a diaphragm type fuel pump, which is mounted on the side of the block. It is operated by a gear driven eccentric shaft through a rocker arm on the fuel pump.
REMOVAL & INSTALLATION
- Clean the joint around the fuel pump base and cylinder block.
- One at a time, remove and plug the intake and outlet lines from the fuel pump.
- Unbolt the retaining bolts and remove the fuel pump and gasket from the cylinder block.
- Clean the mating surfaces of the engine and cylinder block.
- Install a new gasket.
- Insert the fuel pump into the block and install the retaining bolts. Be sure that the bolts are tightened evenly.
- Reconnect the intake and outlet lines to the fuel pump.
- Run the engine and check for leaks.
TESTING DELIVERY PRESSURE
- Remove the wire from the coil to prevent starting.
- Connect a pressure gauge into the output line of the fuel pump.
- Crank the engine and read the delivery pressure on the pressure gauge. The pressure should be a constant 1.5-2.5 psi.
- If the pressure is not within specifications or is erratic, remove the pump for service or for replacement with a new or rebuilt unit. No adjustment is provided.