injectors/fuel return - PeachParts Mercedes-Benz Forum

pdxman · #1 09-07-2002, 05:55 PM

After reading archives of posts and recomendations of changing out old fuel lines, that was my morning project. The small 'jumper' lines going from injector to injector appeared to be leaking. I replaced these with (read in a past post) small engine fuel line(clear). After I cleaned the engine up from the fuel mess and did some test driving, I notice a leak from front injector. You can see in the picture attached. I also notice that the fuel is bubbley in the new injector lines I installed. Is this normal

1979 240D

#2 09-07-2002, 06:07 PM

The bubbles in the lines are normal. There was air in them when you installed them, and little fuel acutally passes through these lines. They will eventually clear out over time. As for the leak, verify where the fuel is coming from. If from one of the new lines, make sure that the cut was clean and even, and that the line is fully installed over the injector nipple.

JimSmith · #3 09-07-2002, 06:54 PM

pdxman,

The clear plastic lines look pretty cool, but I have never seen anything in this application but the black rubber hose material covered with a fabric that fits very snuggly over the nipple. Using that stuff (from the dealer) I have also never had a leak on a newly installed hose. It is a real pain to get on or off, but it is pretty reliable.

After time they degrade and the fabric soaks with fuel, giving a visual indication of the leak to match the usual odor that alerts you to the issue first. Good luck, Jim

pdxman · #4 09-07-2002, 08:08 PM

The hose fit on the fittings perfectly. Not loose, not too tight. The old fabric ones were saturated with fuel. The leak appears to not be coming from the hose, but rather the base of the injector or near the hex bolt.

#5 09-08-2002, 02:12 AM

pdxman,
You should be using the German braided fuel lines. Jim is correct on the explanation on why to use it. I also believe that the German fuel line is easier to pull off when if you need to get any air bubbles out of the system. I am sure there are many more reasons why not to use it, which I am sure someone else will get into.

#6 09-08-2002, 10:19 AM

123c, using the yellow fuel line is harmless. It was actually recommended to me since the regular lines were not to be found anywhere where I live. The fuel line is rated for oil based fuels, and will hold up to diesel. I used it myself on my 80 240D that I later sold to Leathermang. AFAIK, he is still using the same fuel lines I installed. The fuel line is readily available in the same size as the stuff sold by MB. Having the proper size matters more than what color the stuff is. When I get back to working on the '75, I will be putting the same line on it as well. I like being able to see the fuel inside, and only paying roughly half the cost of the dealer part. As for the air bubbles, they exist in the black line as well, you just cannot see it.

In pdxman's case, it sounds like he has a leak around the injector seal between the injector and prechamber in the head - another cheap fix.

dabenz · #7 09-08-2002, 10:27 AM

The return lines look like Leathermang's trick: using weedeater or chain saw fuel lines. Perhaps should be using Stihl (german) brand! I think a good solution, albeit a two or three year solution vs seven or ten, when you can't find the original or can't wait for a place like this web site to ship to you.

Pdxman, patience may be in order here for those lines to seat. If the leak isn't bad and doesn't dry up in a couple weeks then start considering your options.

pdxman · #8 09-08-2002, 10:41 AM

In pdxman's case, it sounds like he has a leak around the injector seal between the injector and prechamber in the head - another cheap fix.

Thanks DIESELPOWER. What tools/supplys do I need to fix this? Are there torque specs for tightening the injectors if I need to remove?

I also think the fuel lines I installed will hold up. They fit snug and are not leaking.

Dabenz...You in Eastern North Dakota? Anywhere near a town called Wahpeton?

dabenz · #9 09-08-2002, 10:52 AM

Pdxman, 85mi N and 15mi W of Wahpeton (as the crow flies). In the suburbs of Cummings, pop. 100.

leathermang · #10 09-08-2002, 03:18 PM

WHOA GUYS, some of you are getting carried away without regards to FACTS...

The fact is that the clear or light green bypass lines on the 240d which I bought from Diesel Power were leaking ... and Tom Cane was nice enough to replace them at the time he did the FAQ pictures for setting the injection pump timing... BillTX was a witness to that event...

So , not only was this not " MY Trick " .. I am with TCane, JSmith,123c,etc on recommending the factory hoses for this place on the engine... , Greg

PS, I love my Stihl chainsaw... but don't know if the size of the lines or the elasticity would be correct.... but do know the factory ones will work great...

190D22 · #11 09-08-2002, 05:17 PM

Hey guys this thread is exactly what I need now. I was cleaning my 190D and I could smell fresh diesel. I open the hood and start nosing around and I notice my #4 (closest to the passenger comparment) injector has fuel leaked out around it and the fuel line that you guys are discussing is saturated in diesel. Would this line going bad create diesel to be collected around the injector? Or do I need to do more than replace the lines, like the injector seal as Diesel Power brought up? I can take pics if you like to see what I'm dealing with here.

How hard is replacing the lines? How hard is replacing the injector seal?

Oh yeah, I've notice lately my car will get into irregular idles after I put it in park or neutral, almost like it's skipping and obviously shakes when it does this. To cure it I have to rev her up to 2000 rpm for a second or two and let it down and is fine. Would these two things be related (injector leak and idle problem)??

Thanks in advance!

PS my mileage was killer at last fill up, 33 mpg all city driving!!!

#12 09-08-2002, 07:13 PM

Quote:

Originally posted by leathermang
WHOA GUYS, some of you are getting carried away without regards to FACTS...

The fact is that the clear or light green bypass lines on the 240d which I bought from Diesel Power were leaking ... and Tom Cane was nice enough to replace them at the time he did the FAQ pictures for setting the injection pump timing... BillTX was a witness to that event...

So , not only was this not " MY Trick " .. I am with TCane, JSmith,123c,etc on recommending the factory hoses for this place on the engine... , Greg

PS, I love my Stihl chainsaw... but don't know if the size of the lines or the elasticity would be correct.... but do know the factory ones will work great...

That is a bummer that the lines started leaking.

I had really thought that I had found a suitable substitute for the OEM lines.

On that note pdxman, look into the OEM stuff before dinking with the injector itself.

pdxman · #13 09-08-2002, 08:09 PM

I'm not one to argue with experience. So I'll take everyones advice on using stock material. Any idea which items I need to order from FASTLANE? They offer several items that pertain to this.

Thanks for all the help.

dabenz · #14 09-08-2002, 09:39 PM

Leathermang, please accept my humblest apologies. I was under the impression that the weedeater/chainsaw fuel line was a trick that worked, and I stand corrected. I love my Stihl chainsaw too, and my Stihl weedeater.

#15 09-08-2002, 09:57 PM

pdxman,
Fastlane offers the fuel line, and I believe they call it looping return line. Another good sourse for the line is at a good foreign auto parts store. I got mine at my local foriegn auto parts store; I think I paid a total of $3.00 for around 3 feet.