Idle problem 250C - Mercedes-Benz Forum

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post #1 of 3 (permalink) Old 04-23-2009, 01:06 PM Thread Starter
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Idle problem 250C

Hi, i'm new to this site (and to the world of Mercedes ownership) and joined to see if I could get some mechanical advice.
I have recently purchased a 1970 250C, the car is in decent shape and runs well, or had run well.
Here is the problem, I was driving one day and ran out of gas (dash lights burnt out) figured I had enough gas but guessed wrong. Ever since that happened the car has had problems with idling.

Turn car on and it idles fine

Drive car and it revs and drives fine

Come to a stop and let the car go back to idle, say at a stop light and it cuts out.

Now I hadn't seen this problem before I let it run out of gas so I figure it must be related to that.
Any advice on this would be greatly appriciated.
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post #2 of 3 (permalink) Old 04-23-2009, 01:39 PM
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Date registered: Jan 2008
Vehicle: 1973 W115 200 /8
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Most likely your fuel system is polluted now..
That day you ran out of gas, you drained the tank and got some "bonus" particles along.. They're now stuck in fuel-line, fuel-pump, fuel-filter, and also possibly in the carb itself..
A total clean-up seems to be the most recomended procedure here.

Unclip the fuel-line at the bottom left front side, both lines. (Under the steering-gear)
Drain the system there first.. (Collect the gas, filter it through a coffee-filter, and re-use later)
Unscrew the cap of the fuel-pump.. Clean it properly.
When re-assembling. Put in a fuel-filter on the IN-line..

The carb is a much bigger job to clean.. So I would have waited with that job, to see if those first steps does it for you..
When you test drive, you can try to give it full throttle several times, when the car is HOT of course !! That also can help loosen up the particles that might be lodged in the carb..
If the car now runs fine, then you won't have to dissasemble the carb..
Good luck !

1991 W140 400 SE - SOLD !!
1973 W115 200 -For sale as project.
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post #3 of 3 (permalink) Old 04-24-2009, 04:41 AM Thread Starter
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Thanks for the advice, i'll be trying it out soon.
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