300 TD fuel problems

[Exekiel69]

My Buddy's car was sitting for about 20 years before it landed on his lap, since then He has replaced several fuel filters. I suggested to drop the tank and clean it instead but he didn't have enough time and rather drained it from the plug under the tank. A couple days ago the fuel filter was clogged with what looked like dark sand, this was the little in line filter not the big one but I think the other one is clogged as well, this caused the car to be low on power (expected) but also the tranny wont shift until you really stand on it or let go of the go pedal and then shift, is this related to the lack of fuel?
He'll get a new filter today but I wonder if there is something else going on. The car always run like a champ, I'm impressed but this last issue changed it all.
Any tips?

Also there is a little strut I believe it holds the belt tensioner down and is missing the rubber mount on the top, can I just rig a little rubber isolator to this or are this parts easier to find?


Thanks.

 

[The Warden]

Sounds like algae in the tank...he'll be light-years ahead if he pulls the tank and has it cleaned out. Otherwise, some biocide and a steady stream of fuel filters, and it'll clean out eventually

Re: the tranny, that sounds like a vacuum leak. When it does shift, how firm is the shift?

I would recommend taking a look at these two threads:

http://www.peachparts.com/shopforum/diesel-discussion/54776-bowden-cable-adjustment.html

http://www.benzworld.org/forums/w123-e-ce-d-cd-td/1398680-bowden-cable-adjustmen.html

Both threads start out talking about adjusting the Bowden cable that goes between the throttle linkage and the transmission, but goes on to talk about adjusting the modulator valve, among other things. A MityVac would be a good investment, for the tranny and for the other vacuum systems on this car (climate control and door locks, among other things).

Hope this helps some...good luck!

 

[Exekiel69]

Thanks again, I will look into it and get to work. My buddy drives the car like it is a speed car since at first it would respond very well but I fear that if something like this fails He wont notice it and break something in the process. I would hate to see a good diesel car go to waste.

 

[Exekiel69]

Also, along with the tranny shifting too late or high on the rpms, it feels like there is no power when it used to have lots of it. I thought it could be a bad lift pump from all that algae but I don't have My pressure gauge here to check. I could not find a replacement for it even on the peach parts site.

Btw thanks for the links .

 

[The Warden]

IIRC the "lift pump" on these is a permanent part of the injector pump, and doesn't fail nearly as often as on the 6.9l/7.3l. As to the lack of power...my guess is that the new fuel filters are clogged. Given that these cars aren't exactly powerhouses they are more sensitive to fuel filters being badly clogged. Also, if there really is algae in the tank, the in-tank strainer is probably at least partially clogged. I'm assuming the 124 is similar to the 123 in this regard, but the fuel feed line to the engine should come out the bottom of the tank...if you look at where the fuel line goes into the tank, there should be a large-diameter hex fitting around where the hose threads into the tank...this is the strainer. This picture is for one out of a 123, but I think the 124 strainer is similar.

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Unfortunately, there's no way to get that out of there without taking a fuel bath, unless the tank is empty...but I would strongly recommend taking a look at it. 9 times out of 10, you can clean up the strainer with carburetor cleaner or something like that and won't need to actually replace it (although you may want to replace the O-ring). Might also get you a sneak-preview of the condition of the inside of the tank.

Beyond that...what shape are the injectors in? You may also want to check the timing chain stretch (and, by extension, the pump timing)...and, of course, make sure that the turbo is happy and there aren't any boost leaks.

Algae can really choke these engines!!

 

[Exekiel69]

I will check into all that. btw the link to that MB site is good , I think after some reading the problem should be a vacuum leak since it was sudden, one day everything perfect with lots of power and the next day complete ****. I didn't look into the turbo since it was hiding under a bunch of sheet metal and all kinds of covers but I did replace all the little vacuum hoses I could find and still no change. Down hill, it will shift through all gears but under load it will rev really high and not shift with the added lack of power.

The injectors are the same it had from factory I believe with only 70k miles I think, the chain and timing I have o idea how to set them or service them so I'll have to learn that.
I will drop that tank and clean it, the filters are new and I can see fuel coming in through a in-line filter.
I will provably have to drive the car up with some ramps and take a good look at all the vacuum hoses, I still can't find that bowden cable to adjust the tranny when I look from the engine bay.

Thanks again for Your help.

 

[Arborigine]

Bite the bullet and clean the tank. Always start with the known and simplest problem. The trans will probably function normally once power is restored to the engine.