Engine stalls and won't rev

[mb1902.2]

I have a 1984 MB 2.2D and although not fast, very enjoyable to drive and great fuel mileage. Went to the mountains and it stopped (Yes - snow storm approaching, roads got closed down, no hotels, local mechanic couldn't fix it etc.) Towed it back and got it started, and here's what happens:

When the car comes to a stop, the engine has a tendency to stall. When cranking, it runs for about 2-3 seconds, then goes to very low RPM and eventually dies. I replaced the fuel filters thinking that they were plugged up, but that was not it. As I drove up a hill today, it sputtered, extremely low RPM again, and stalled. I waited a couple of minutes, and same thing again: Starts up great, runs for 2-3 seconds, then low RPM and it stalls. Sometimes when I floor it while trying to get it started it's still on low RPM, but picks up a little bit, then goes to low RPM, then picks up a little more, then goes down again. If I try to put it in gear, it moves forward, but has no power and gives up after 1/2 sec.

Does this sound like it could be the fuel pump?

I also thought it could be dirt clogging up the lines, but I find that more unlikely after I drove it on the freeway and it worked fine.

Thanks for any insights/suggestions that you may have!

[Jimmy Joe]

Still sounds like fuel.
What about that strainer in the tank?

[MS Fowler]

How much fuel came out when you changed the in=line filter? Depending on the fuel level in the tank, and the angle at which you are parked, a fair amount of fuel should be trying to run out of the hose when you remove the in-line filter. If little, or no flow, I, too, would suspect a clogged tank strainer. By the way, was there any noticeable color to the in-line fuel filter?

[mb1902.2]

When I changed the inline filter there was some fuel dripping out of the hose from the tank, perhaps a small stream, but not much. The inline fuel filter had turned black on one side.

Will change the strainer next.

Thanks!

[SD Blue]

From your description of the in-line filter, it sounds as if you may have critters growing in your tank or picked up some very dirty diesel. It would probably be a good idea to pick up some Biobar and 3-4 of those in-line filters.

I managed to pick up some of that dirty diesel while traveling for the Christmas holidays and it took Diesel Purge, filter changes, and Marvel Mystery Oil to get rid of the nailing.

[mb1902.2]

SD Blue:

That makes sense. I checked the inline fuel filter that I put about 2 weeks ago, and sure enough, there is a little black spot on the bottom of it.

I have Diesel Purge and various other Lubro Moly products on order. Replacement strainer and additional fuel filters are also on order, so I'll have a busy next weekend.

I'm cleaning the engine, finding all sorts of loose vacuum hoses and re-connecting them, so the excursion under the hood has been beneficial.

Thanks!

[MS Fowler]

Sounds like you are well on your way to fixing this problem. Pulling the tank strainer is messy, but not difficult. One local indy, me that he never rtank strainers--He removes it, cuts off the screen, and reinstalls it. Then he instakks a "Y" fitting in the fuel line at the inline filter, and installs 2 inline filters and watches them carefully.
I think its better to pull, and clean the tank, and then replace the strainer. At least you know the tank is clean on its inside.

[SD Blue]

Here is how I did my fuel tank screen: No muss no fuss.

You need a 5 gal. fuel can (depending on remaining fuel). About 5' of vinyl tubing large enough to fit over the flex tubing coming from the tank and small enough to fit in the fuel can spout. Hemostats or locking vise grips to clamp the hose. Unclamp the flex hose coming from the tank and insert it in the vinyl tubing. Release the hemostats. Go have a cup of java and in a few minutes the tank will be empty. (BTW, the screen takes a 42mm socket)

[Brian Carlton]

Originally Posted by SD Blue

BTW, the screen takes a 42mm socket

Can you please check this? The SDL takes a 46 mm socket (1 13/16 also works).

[SD Blue]

Sorry, did not mean to steer someone wrong. It is a 46mm. Thanks

[Brian Carlton]

Originally Posted by SD Blue

Sorry, did not mean to steer someone wrong. It is a 46mm. Thanks

Just go up and edit post #8 and we can get rid of #9, #10, and this one.

[kerry]

Fuel delivery problem somewhere. Ran into the same problem with a 72 Chevy wagon I had. Changed fuel filter and fuel pump and it would still act that way. Took me about 3 hours to climb over I-70 100 yds at a time before it stalled. Coasted downhill back into Denver. Finally figured out that the PO had added an additional fuel filter in line just after the fuel tank!
Before tearing into the tank, get a pop bottle filled with diesel in the engine compartment, drill the cap and put in a piece of fuel line and feed it to the fuel filter. See if it runs fine that way. If it does, you know the problem is upstream.

[MS Fowler]

No one has mentioned this, but what about a clogged vent line?
Is there any noise while removing the fuel cap--like a "wooosh"? That sound would indicate a plugged vent.

[mb1902.2]

I did notice that there appeared to be a vacuum in the tank. I have not noticed this before, [the troubles began] but it seems to be gone now. Hard to say - I have not driven it much as it tend to stop in the most inconvenient places. I was poking around earlier finding the strainer and preparing to change the hoses under there. I know there is a vent there - I may have unintentinally unclogged it.

Got the fuel hoses and strainer - waiting for Diesel Purge which is supposed to arrive on the 15th before running it though then replacing strainer, filters (again) and hoses.