81SC fuel accumulator question

does anyone know what the lower fitting of the fuel accumulator for? Is there supposed to be fuel in the line after sitting for days? I am trying to tell if I have a leak in the diaphragm. Any ideas?

Not sure what your first sentence says, but here goes.

The accumulator is between the fuel pump and the engine. During operation, the fuel pressure is 75+ psi. After shutdown, the accumulator acts as a one-way valve to hold fuel pressure in the lines from the accumulator to the engine. 30 psi or so, if memory serves.

If you disconnect the fuel pump side of the accumulator (the INLET to the accmulator), there should be just a little pressure in the line. There is a check valve back at the fuel pump also, but it only makes sure that fuel remains in the line after shutdown -- it is not there to hold pressure. If you disconnect the OUTLET of the accmulator, you get the 30 psi or so residual pressure.

I don't know top from bottom fittings. Figure out which one is the INLET and which one is the OUTLET, then apply the above thoughts.

If the accumulator does NOT retain the pressure, it takes a while to get fuel to the engine for your next start.

I have 3 fuel fittings; 2 on top and 1 on the bottom. the one on the bottom is my question.

If my memory is correct, there are basically to types of Accum. The early type only has 2 fittings, the later type has 3 fittings.

Assuming you have the later type, the two on top are the inlet and outlet, the one on the "bottom" is a return to the tank via the return line. Someone correct me if I am wrong, I believe that this 3rd fitting is designed to return excess fuel to the tank if the accum fails.