For the past few weeks I have been having trouble with an occasional loss of power while cruising, but a quick push to full throttle would usually fix it. I chalked this up to partially clogged fuel filters, so today I changed both filters under the hood. I made sure to prefill the filters with diesel and change the o rings on the main filter as well as the prefilter, and to my surprise the car started right up. It stumbled for a bit, but soon settled in to a steady idle and so I figured all the air was out of the system and I drove off.

Just over a quarter mile from my house it lost all power and died so I coasted to the side of the road. It would not restart, only stumble along on the verge of catching, and I quit when it started cranking noticeably slower. After coming back from my house with some tools and extra diesel, I prefilled both filters once again and resumed cranking. After a couple minutes it caught but would only run with me holding full throttle. After another minute or so of it struggling to run, it finally settled into a semi-normal idle and I made it half way home before it died just like the first time.

So now I'm confused and am thinking about everything from leaking fuel line o rings to a fuel pump that isn't working. It feels like it is running off of the fuel I poured into the filter and then dieing when it runs it dry. Why is it not drawing in more fuel and where could air be getting in the system? Thanks for the help.

You should have a fuel strainer in your fuel tank which could be plugged. I'm not 100% certain on a 95 but if the tank has a fair amount of fuel in it you could reverse the supply and return fuel lines to see if it runs. You can check for air if you place the return fuel line in a very large jar and see if fuel and or air is going through your system. Both tests require the engine to run however.

Well I seem to have fixed it. The fuel line that attaches to the top of the prefilter had an o ring that I didn't replace and I guess it was letting air in. I found an o ring I had laying around that was just slightly bigger than the one that was on there and after a quick reassembly and prefill of the filters it fired right up with almost no provocation from the throttle. I'm glad it's running fine now, but a little worried at the same time knowing that if one o ring fails to seal the engine won't run at all.

I had a similar problem which turned out to be the same o-ring to the prefilter. Being able to see the air bubbles through the hard plastic fuel lines was invaluable. They say the low sulfur diesel fuel eats away at the old o-rings. I was chasing 3 fuel leaks at the same time a couple of months ago. I got a complete set from FryerPower which work great. Allow 6-8 weeks for delivery though.

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1995 E300 OM606 NA

Past:
2X1985 300D's
1998 Dodge Ram 2500 Cummins Diesel
1976 Peugeot 504 Diesel

Absolutely fair assessment! Sometimes I ship the next day. Sometimes it takes WEEKS.

Even with every o-ring in stock right now I'm still having problems. Someone ordered two weeks ago and I never got notification.

At this point I'm just rolling with it, but I have to say my give a crap supply has just about run out. The hassle of dealing with the insurance company on the fire pretty much has that tapped out.

Hopefully I can get in next week and streamline my website. Everything except O-rings is going away and I'm going to set up a new email address to receive notifications. My current one gets 200+ spam emails a day.

Jim

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1995 S350D, Green with black leather interior.
Bought January 2008 w/ 233,xxx miles.
I did 22,000 miles during the first year of ownership.