Fuel lines to enigne bay W124 95

[WINGAS]

Folks, I neglected to label the steel fuel lines that run from the tank into the engine bay.

I ASSUME the lower one is the inlet (supply) and the upper is the return.

But I dont like to assume. Which is the feed and which is the return?

tia..

[WINGAS]

Y'all are going to make me "pay my dues" and have to lift the car and actually trace the lines aren't you. Well, hell boys, its a heckuva cool club to join so... havent been under her yet anyway....

[Bio300TDTdriver]

I'll run out to the garage after I finish my blueberry coffee cake. I have an '87 so the lines are probably the same.

Chris

[Bio300TDTdriver]

Upper is supply on my car '87 300TD.

Chris

[WINGAS]

Yumm.... THNX Chris!

I think I'll lift the car and take a look see just so as not to assume anything... after I rig them first as per your instx.

[TMAllison]

The 3rd diagram is yours.

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=124131&M=606%2E910&GA=722%2E435&GM=717%2E433&CT=F&cat=44Q&SID=47&SGR=045&SGN=03

[WINGAS]

Its vague enough to be useless!

Well, when torquing down the injectors, I must ahve pulled one of the return lines off.

A few minutes later I see that that hole , #6, is full of fuel.

So I reckon that I had the return/feed lines crossed as the retun lines filled with fuel. Tonight I'll put the car on stands and take a gander underneath.

Suppose it could have filled through the return line ( the fuel tank is full btw).

Is there any DEFINITIVE way to know which one is feed and which is return?

Other than being carful to frickin LABEL THEM when I disassembled it in great haste?

[TMAllison]

Originally Posted by 427L88

Its vague enough to be useless!

Well, when torquing down the injectors, I must ahve pulled one of the return lines off.

A few minutes later I see that that hole , #6, is full of fuel.

So I reckon that I had the return/feed lines crossed as the retun lines filled with fuel. Tonight I'll put the car on stands and take a gander underneath.

Suppose it could have filled through the return line ( the fuel tank is full btw).

Is there any DEFINITIVE way to know which one is feed and which is return?

Other than being carful to frickin LABEL THEM when I disassembled it in great haste?

The diagram tells you which is feed vs return. Diagram is subjective in detail but you should be able to figure it out by the devces each line connects to enroute from tank to engine.

Check inj #6 and make sure it has a return line plug installed on the last nipple.

[WINGAS]

Ya, thanks Terry, I cut the old "slug" out and put it it new line.

Well, the good news is, when I swtiched the fuel lines, the rest of the system primed a bit, fuel to the preheater now.

So it looks as if the feed line runs through a valve 203 after exiting the tank and then it looks like ( in their "impresionist drawings" ) that line #14, goes into the preheater.

FOR THE RECORD, as they enter the engine bay, the LOWER line is the feed line, the UPPER is the return on a 95 E300 D 606.910

Different than Chris 87 .

Saw no valve outside the tank, but the feed line plugs into the bottom of the tank.