85 200td, No fuel to Pump.. - PeachParts Mercedes-Benz Forum

bpeters2 · #1 06-23-2008, 09:11 PM

SO....My rear brakes blew out, so I fixed them by running a new length of hardline from the master cyl. back to the rear axle..not too bad of a job. When I tried to start the car after words it started right up then died after 30 seconds. I did a little investigating and found that the Priming pump (hand operated) was not pumping ANY diesel (I disconnected pump output line to test)...moreover, it was pumping WVO just fine (when I switched the intake valve). I'm thinking that I may have busted loose one of the incredibly rusted fuel lines while I was monkeying around getting the brake line into place and into those annoying rubber spacers (which seem to be the #1 place for rusting). Does this sound like a probable diagnosis? One of the fuel lines felt like it had a lot of give towards the fuel tank. How hard is it to replace the fuel lines from the tank all the way to the front of the car...would replacing all the line with rubber fuel line be OK (I'm kinda in a bind for $$ and time) Do I need to drop the fuel tank to gain access to where the fuel line enters/exits the tank? Unfortunately my car is 100 miles away and I only have weekend access to it so I need to get all my ducks in a row before next weekend. Thanks a lot

Chad300tdt · #2 06-23-2008, 09:18 PM

I posted this in the other thread, but here it is just in case.

Both the feed and return lines on my wagon were leaking under the subframe. Rather than drop the subframe and replace the lines I just used rubber hose.

Check my thread with pics:
Leaking fuel lines repaired today

EDIT: I took me about an hour to do this repair, including the time to run to the PepBoys to get the fuel line.

bpeters2 · #3 06-23-2008, 10:10 PM

Thanks Chad!

Did you replace the rubber lines that come directly from the fuel tank... If so, do you remember what size fuel line it was?? Ideally I'd like to replace those and then run the length with one piece of rubber hose all the way to the engine bay.

P.S. I was just looking at your gallery...nice license plate!!

Chad300tdt · #4 06-23-2008, 10:33 PM

Quote:

Originally Posted by bpeters2

Thanks Chad!

Did you replace the rubber lines that come directly from the fuel tank... If so, do you remember what size fuel line it was?? Ideally I'd like to replace those and then run the length with one piece of rubber hose all the way to the engine bay.

P.S. I was just looking at your gallery...nice license plate!!

Yup, I replaced the rubber lines directly out of the fuel tank all the way up to where my hard lines had NO rot. It was between 4' to 5' of hose each for the feed and return. I bought 1/4" (I.D.) line because that's what was available. It worked, but it took some effort to get it over the nipple of the fuel tank and over the cut end of the hard fuel line. I would have bought 5/16" if they had it. (which is what the stock rubber hoses are)

If you look at the pictures in my link, the one pic is coming right out of the tank at the rear dif. and the other is where I cut the fuel lines up by the front driver side door.

Also, the fuel line I got from pepboys was rated for diesel, but I don't know how long it will hold up for WVO. I'd imagine it should be fine since it won't see much heat under the car.

Thanks for the compliment, but that was just some wishful photoshopping on my part.

Nothing else is photoshopped, I thought that would be cooler than just erasing out my actual plate number.

bpeters2 · #5 06-24-2008, 09:25 AM

Bump...and...could these symptoms be due to a clogged fuel filter? I'm wondering either filter is clogged will it start pulling in air from some sort of "vent" to avoid excess vacuum within the fuel system. Seems unlikely that the fuel filter would suddenly clog however.

Chad300tdt · #6 06-24-2008, 09:31 AM

My guess is you're pulling air in the leak in the lines. The fuel tank has a vent that would keep a vacuum from building. If they are as rusty as you allude to, they could have multiple entry points for air.

bpeters2 · #7 06-24-2008, 10:27 AM

I have the fuel system "re-routed" due to the install of a WVO kit. The way I have it now the Fuel filter(s) are upstream of the fuel pump so if there was a clogged filter it may create a vacuum between the filter and the pump. I just got off the phone with phil and ordered some parts, I'm going to replace the fuel filters this weekend. Figure I might as well since I never have before. I suspect the fuel lines too..just want to make sure I'm prepared for whatever I may find this weekend when I get a chance to look at the "ole rust bucket" again.

bpeters2 · #8 06-25-2008, 09:35 AM

Another piece of information I forgot to include: I Found a little piece of of fuelline (steel line) that looked wet so I cut it out and spliced in some rubber hose. I'm not sure if it was the return or the supply line, but when I cut it, no fuel spilled out. I'm not sure about the plumping of the fuel tank, but does this indicate that the screen is clogged. Could it have just been the return line which I had filled with air after pumping air through the system? My fuel tank was a little low and the car had been up on blocks for a while so I thought the pickup might be not submerged..so I added 5 gal of diesel and still no fuel was getting to the pump after pumping the primer pump (and cranking the engine) for a while