If you've got an old Merc and are having fuel problems - and hey, there's plenty of us out here looking for salvation - take a tip from me and start at the source. Drop your fuel tank and give it a good cleaning. As you'll see from the photo, 18 years of crap buildup in my 87 300E tank makes for unattractive viewing. There's about 8-10 litres of fuel in the bucket and the water and rust is about 2cm deep. Had I done this earlier, I think I would have saved myself buying a new fuel pump, two fuel filters, EHA, fuel pressure regulator and fuel distributor. Plus 12 months of fuel injection hell.

Car's running great now. But then its got a clean tank and all those new and reconditioned parts.

As an aside, watch out that cleaning out the corrosion doesnt open up any leaks. I discovered two thin patches that broke through once I'd dislodged the rust holding them together. Took the tank to a radiator repair place where they were able to braze a repair patch it.

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1987 300e manual 250,000 km (sold)

When you had the tank out and at the radiator shop did you have them braze in a drain plug at the lowest part of the tank to aid in future tank cleaning? A drain plug would alleviate the nexessity of dropping the tank, although dropping it to inspect for leaks periodically is a good thing.

Tim

Now that is a good idea. Wish I'd thought of it.

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1987 300e manual 250,000 km (sold)

Good information. I've always thought about doing that, though I don't know how hard it is to get that accomplished on my W126. Has anyone ever taken out their fuel tank from a W126?

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1999 Mercedes-Benz S600, 103K miles - garage queen
1988 Mercedes-Benz 560SEL, 89K miles - daily driver
2007 Hyundai Sonata Limited, 31K - daily driver