Need drain fuel tank--bad gas. How ???
Need drain fuel tank.
How do I drain tank ???
Thanks.

Remove engine cover and connect a fuel pressure gauge hose without the gauge to the test port on the fuel rail. Or remove fuel line that goes to the engine off of the fuel filter and connect a hose. In both cases put the hose that you are installing into a gas can.
In the trunk next to the fuse box (between spare tire and battery) remove fuel pump relay, it should be green and it will have a fuse in it. Connect a fused jumper wire between circuit 30 and 87. This will run the fuel pump, wait until the tank is empty.

Eclass,

Youv'e been a big help, but I have a few questions, and still
need some of your help.

I made a fused jumper and connected it as per your instructions.
On the fuel rail, I did something a bit different. I used a regular
valve stem tool, and removed the stem valve, then connected
a hose.

Gas drained well for about the first 4 gallons, then slowed down
a lot, to just a trickle, about 10 minutes to the gallon. I drained
about another 3 gallons, then I disconnected the jumper
because I was afraid that something was going wrong.

So, a couple of questions.
1. Is it supposed to drain this slowly ?

2. Did I screw up the process by removing
the stem valve altogether, instead of using a
pressure tester without the guage ?

3. The gasoline looks much cleaner, not deep urine
yellow like at first, with a separation water line at the top.
Now it's looking clear with a slight yellow tinge., and no
discernable line. Is that right ?

4. After I drained the first 5 gallons, I temporarily reinstalled
the relay, and closed up the fuel rail, and tried to start the
car. It started, which was great, since it was absolutely not
starting before. It is running very rough, but it idles, and I
can rev the engine. By the way, I changed out the CPS a
few days ago and it didn't help. That was before the bad
gas idea came up. Right now, it is idling in the drive way
and still has half a tank of gas. I was thinking of adding s
ome of the dry gas products and see if that helps.
What do you think ? Any advice would be greatly appreciated.

Allso, I am attaching a link to a photo of what I have done.

Again, thanks.
Link:
http://www.panchogun.com/FVWebPhotos/FV-Cars-CLK-Drain-Gas-Tank.jpg

By removing the valve you might have interfered with the operation of the pressure regulator and the siphon jet operation of the fuel tank. Long story short- Not a big deal you just emptyed 1/2 of your 2 sided fuel tank. So you still have bad gas in the tank. Your options are, fill the tank full again and redo, or get under the car and remove both access panels attached to the fuel tank left and right sides. remove the Allen screw plug to access the drain valves no gas behind them. BE CAREFULL doing this next step. Normally you would use a special tool from MB to open the valves but i don't see why you couldn't operate them without the tool they are like a spring loaded valve you can look at them and see, NEVER tried this without the tool. With valves opened the tank will drain. When you are sure the tank is clean, replace the fuel filter and run the pump again to clean out the line to the engine before starting car.

Thanks.
A couple of questions:
1. If I use a pressure gauge, like you recommended, do you think it will drain the rest of the gas ?
or,
2. If I fill up again, will it push the bad gas from one tank to the other, and leave good gas in one tank, and bad gas pushed to the now empty tank ?
and
3. The valves you mention, do they connect the tanks, sort of like an equalizer, so that I don't have the siphon problem ?
4. Do you know the part number of that tool, and where I might be able to get one ?

Again, thanks. Your a great help.

Mercedes tool # 202 589 00 90 00. cost is ?? You can order one from the dealer. Have you called the dealer to see what the charge would be for them to drain the tank. The cost of them draining the tank may be the same price as you buying the tool. Maybee you could find the tool on E-bay and then when you are done with it put it back on E-bay. Although if you put the valve back into the fuel rail on the engine and connect the correct type of hose, refill the tank, the tank should drain correctly. But that may be a waste of gas. Go to this web site www.mercedestechstore.com (http://www.mercedestechstore.com)
select- Access our Training Print Files
go down to the heading - Files for 508 Systems 2 training
select - 508 Systems 2/508 HO Part 07 Fuel supply (WJB) 04-01-01.pdf

Note: you have a Model 208, this will discribe your saddle tank and the operation.

http://www.mercedestechstore.com/pdfs/508%20Systems%20II/508%20HO%20Part%2007%20Fuel%20supply%20(WJB)%2004-01-01.pdf


or try this link.