I'm puzzled about a problem I've been having with my 1976 240D (W115 chassis). Last weekend, I filled the tank, and drove around quite a bit in warm weather. After resting for an hour in my garage, the car only got as far as my driveway and the engine stalled and wouldn't restart...didn't seem to be getting fuel. A few days later it started fine. I had some work done this week at a shop to replace my water pump (was leaking coolant) and the car stalled again right after a warm start again. Finally it started and ran OK, so I drove right back to the shop.

The tech determined my primer pump was bad and replaced it with the upgraded style. Leaving the shop yesterday, the car stalled twice right after starting but then ran fine (should have left it there!). Drove to my friend's house and it was losing power occasionally and didn't seem like it was running quite right. After 3 hours of sitting at my friend's house, it started and then stalled again. It won't start now; it's like it's trying to catch but just can't quite. Another funny thing is that over the last few months I've noticed it starts great cold and not as great when warm.

Can't figure it out. Both fuel filters have been replaced recently and the prefilter is clear and has no air bubbles. My uneducated guesses are either the fuel tank strainer is clogged, injectors are clogged, fuel line somewhere is clogged, or perhaps it is an air issue, like the breather system? The car is kind of a restoration project as it does seem like it was pretty neglected by the former owners, and I wouldn't be surprised if some rust, dirt or algae in the fuel tank has broken loose and clogged something up. But I'm not sure how I'd go about draining a totally full fuel tank.

Any advise & suggestions would be greatly appreciated. Thanks.

katja,

Classic symptoms of not getting enough fuel. If the filters were replaced recently its might be the tank strainer is plugged. You could have a fungus problem. That is usually what plugs the tank strainer.

See my reply to pharaoh to test the fuel stariner.

No need the remove the tank to have it cleaned. The filters will catch the dead fungus. I had to replace only one inline filter after I treated my fuel system with Biobor to kill the fungus.

P E H

As far as draining a full tank...that does suck, but you're just going to want to get as many clean buckets as you can--make sure you have enough before you start--and wait it out. Make sure to remove the fuel filler cap while it drains so that the liquid does not create a negative pressure behind it as it leaves (in other words, so it drains faster).

The tank itself may require extensive cleaning to get rid of algae, meaning removal from the vehicle and taking it to a shop. Or you could just try using algaecide in your fuel, but you may still get future clogging in your strainer from the remnants.

Good luck.

__________________
"I would rather be ashes than dust!
I would rather that my spark should burn out in a brillaint blaze
than it should be stifled by dryrot.
I would rather be a superb meteor,
every atom of me in magnificent glow,
than a sleepy and permanent planet.
The proper function of man is to live, not to exist.
I shall not waste my days in trying to prolong them.
I shall use my time."

-Jack London 1876-1916

1983 300CDT (running WVO since 12/05)
1981 300SD (parts car)

Thank you for the advice. The problem seemed to be a leak at the main canister fuel filter gasket (never would have guessed, since I replaced that filter months ago). The car runs fine now and has normal power. I ran it up some hills and got some of the carbon out...no smoking at idle now.

I'm still not satisfied everything is fixed with the fuel system. It seems to take longer to start than it should, and I still smell fuel when the car is sitting and appear to have a leak, somewhere...but can't find anything.

I hate to think of taking the tank out to clean it...cleaning the oil bath air filter out was bad enough!

Are there any particular products that are good at cleaning the fuel system? I've been using Hi-Test (Lubro-Moly) in the tank but nothing else. Also haven't done a diesel purge yet but maybe that'd be a good idea?

Thanks,
AC