w123 280ce tank return pipe orifice clogged - PeachParts Mercedes-Benz Forum

geoffreymbrown · #1 05-30-2016, 07:59 AM

Quote:

Originally Posted by Frank Reiner

gmb:

The opportunity to place ignorance on display cannot be passed up:
Why is there a restriction in the return line? Such has not been observed elsewhere.

This is for a different model, but the problem is the same --

Fuel Tank Strainer, Fuel Tank Insides, Swirl Pot, Return Line Venturi - Mercedes-Benz Forum

The venturi gets clogged -- in this case after sitting for several years. There's no direct access and it can be challenging to unclog.

geoffreymbrown · #2 05-30-2016, 08:44 AM

Using a 2+ foot section of aircraft cable spinning in reverse with a drill succeeded in rooting out the blockage.

Graham · #3 05-30-2016, 10:20 AM

Quote:

Originally Posted by geoffreymbrown

This is for a different model, but the problem is the same --

Fuel Tank Strainer, Fuel Tank Insides, Swirl Pot, Return Line Venturi - Mercedes-Benz Forum

The venturi gets clogged -- in this case after sitting for several years. There's no direct access and it can be challenging to unclog.

There are two holes really. The one in the jet and then the aperture around it. The return line jet causes fuel from bottom of tank to be sucked into the swirl pot. The jet can be cleaned as you described by rodding it out. But the aperture around it is hard to get at. When that is blocked, cars have been known to run out of fuel when level gets to below the top of the swirl pot.

This Pelican link is about the Porsche swirl pot which is similar, but not exactly same as those on Benzes. It has pics that show the fuel entry aperture adjacent to the return line, more clearly.

CIS Gas Tank - Pelican Parts Technical BBS