Hello everyone...
I own a 300SD, in excellent condition (Will post pics), but I recently began losing power on highways, then on hills. From what I had read, I assumed that it was either the fuel filters, or the tank vent valve, so I decided to at first, change the primary filter. After doing so, I had a noticeable improvement but still, could only hit 15-20mph on hills... So, I moved on to the secondary filter...
When I changed it, I unscrewed the old filter, poured the fuel from it (looked clean) into the new one, then screwed on.. I have an old white primer pump, but I primed it until fuel squirted out of the top...

Anyhow... I started the car up just fine, it ran for about 30 seconds, then sputtered off... It won't start now, I've worn the battery out once (Own a recharger).. I'm assuming there might somehow be air in the line somewhere? Is there a valve or something that would release air from my lines? Is my diagnosis even close to correct?

I appreciate any replies, I'm a student at Marshall University, and I'm stuck with no transportation, with school starting in the next couple weeks..

Thanks!

First thing check your lines, you might of ruptured a old fuel line somewhere.
If you think that is fine then but it still dies after firing up, get a bucket or something you can keep clean and put some diesel fuel in it. Then run that straight to the main fuel filter (or to pump if you want to risk it) and make sure the pump isn't the problem.

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I am not a post whore, I am a car enthusiast.
86 190D 420k and counting

hello, i think the filters are the same for my 240d, after i put the new filter on i loosen the other smaller nut that the incomming fuel line attaches to and then use the primer untill fuel comes out.....hope this helps, oh also check to make sure you dont have small cracks on the hoses at the primary filter and the clamps are tight..Bill

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Gretchen 1981 240D 4-spd 213,000 mi
1979 240D 4-spd 298,000 mi parts car

1994 BMW 325is
1991 Dodge turbo diesel
1997 ford expedition

BILL

I believe you have air trapped between the Fuel Injection Pump and the Injectors. Air got inside of the Hard Lines.
When this happens (after the battery is recharged) loosen all of the Hard line nuts up by the Injectors and crank the Engine until you see Fuel out from under the Hard Line Nuts. When you see this tighten the nuts and try to start the Car
If you have the old style Hand Primer be sure to push it all the way down and screw it back snug so that it seals.

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84 300D, 82 Volvo 244Gl Diesel

I agree, I'll try that tomorrow during daylight hours.
Thanks a lot, and I'll keep ya updated.

That worked great!
Thanks a lot.. I'll post some funny pictures as soon as I can get them, car got caught in a flood.

Feels good to have a working car.

Good Deal!
Keep in mind that this same air trapping problem can happen if you run out of Fuel; keep enough Fuel in the Tank or be sure you keep a 17mm wrench in the Trunk so you can do the bleeding on the roadside and not deaden your Battery.

Also, I had the same issue the last time I changed my Spin-On/Secondary filter.
I was in a hurry and did not pump the Hand Primer enough to bleed out all of the air out of the IP Housing and ended up having to loosen some of the Injector Hard Line Nuts to get the air out.

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84 300D, 82 Volvo 244Gl Diesel

It was just air in the hardlines? I normally just pull another car over and pre-jump my diesels while I am cranking the crap out of them so I don't have to worry about killing the diesel battery.

So glad to hear you didn't have to replace hard metal or rubber hoses in this weather (wherever you are?)

oh and you guys need to get bigger/better batteries, I have no hand primer on my benz nor have I ever on any VW diesel I owned and only once did I really kill a battery after the hard fuel lines were off and no fuel in lines from tank to pump.

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I am not a post whore, I am a car enthusiast.
86 190D 420k and counting

Its great that you finally started the car....in my experience, routine fuel filter changes, or any work requiring removal or the "spider" hard lines, usually means a real PIA to start the car again because of the air trapped in the system. Even when I prime the filter, "crack" each hard line at the injector to bleed, it still requires a bit of cranking to start.

I do second the above recommendation to check rubber fuel lines for cracks...better yet, if they are old, just put in new ones. I once had a real problem losing power etc., brought the car to mbz mechanic, and after a fair amount of money, the car still had the problem, only to find that the rubber hose from the hard fuel line to the primary filter was old..when I would tighten the clamp, it would distort the cracks in the line allowing air to enter the system. I replaced this hose (at a cost of about $1.50), and the car was just fine

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1984 300TD Wagon, 407,800 mi (current daily driver)
1985 300DT Sedan, 330,000 mi (gone to that great autobahn in the sky)

The Bosch EPVA IPs that are on my Volvo and the VW Rabbits are self bleeding and I have heard the newer Mercedes pumps are too.

Even nicer the older inline IPs of many different makes used to have a bleed screw that you could open on their housings. It made hand priming or cranking to bleed out air a much shorter and surer job.

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84 300D, 82 Volvo 244Gl Diesel

I know that this works , but your really beating up on that starter. Bleed it and it works great, your starter will last longer.