Last Injector Return line?
 

Is the last injector return line supposed to be plugged? I looked under my 220d hood today and the last injector return line was a short stub that was open and squirting fuel. On my 123 it has a plug in it. Can I just seal it off somehow like with a screw?

yes.

It sounds like the hose swelled and spat out the plug. Probly anything is better than nothing to block it but should replace the piece of hose too. I can send you a spare bit of bypass hose if you need it.

Allot of fuel can come out of an unplugged return line. Yesterday I fueled up, checking under hood, of course, got home, went in the house, came back out an hour later and theres a big puddle of fuel under the car. It was leaking at a return hose connection on #3 injector (hardest too get to) . The car was stopped and fuel was running out the return hose when I pulled it off the injector. I guess I have never changed return lines on a 123 with a full tank of fuel:D I can imagine how much would be squirting out when under way.

I had the return hose come off on the highway. Stopped after smelling fuel for a while, found the hood pad soaked and the hose on top of the head. Whadda mess!

A broken injector return like can quickly pump out 1/4 tank before most people will notice it.

I have heard that theres just as much fuel "returned' as burned.

The injector return lines share the same common line as the injection pump pressure regulator's return line. There is very little leakage in the injectors.

403 070 00 55 should be the part number. Less than $5.

BTDT! It started leaking on a trip while about 500 miles from home. I managed to cobble together a patch and then bought the cute little piece of hose with plastic plug. That was about 1988, I think they have a one piece plug now.

I probably lost a quarter tank of fuel before figuring out what was going on. I am quite sure that a LOT more fuel comes out that plug than is burned in the engine, that is if it is totally gone and not just dribbling.

Buy two - always carry one as a spare. That way you'll likely never need it. Works for me. :)

Len
'83 240D 346,000 miles original owner

The volume of fuel returned far exceeds that which is actually injected.

LOL, Yesterday after my "oil spill" I grabbed a couple chunks of return hose from the shop and stowed them in the trunk of my cars :)

The return from the IP is far greater than what is injected but the return from the injectors is tiny.

But......if the end of the injector return lines is open, some of the IP return will back feed from the banjo bolt on the filter thru the injector return line and create a big leak. Fortunatly, the pressure is low so just plugging the stub with a golf tee will hold for a while.

If you are looking for an excuse for another gauge, hook up a gauge to the last injector return to plug the end.:rolleyes:

A golf T with a hose clamp on it will work well.

-Jim