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Discussion Starter #1
A couple of weeks ago, I posted a thread dealing with the hesitancy I am experiencing with my 380SL. Initially it was thought that the 500 style timing chain might be at fault, but eventually the recommendation was to get a tune-up.

So, the air filter has been replaced, as have the spark plugs and fuel filter.

Now the mechanic says the problem might be in the fuel mixture control.

He says that when he pushes all the way down on the airflow meter plate while the car is idling, that it makes no difference. He says it should stall when he does that which indicates the control is not operative. He also says the part is VERY expensive, and used parts are normally no good if they have been sitting somewhere on a garage shelf.

Any comments or thoughts would, as usual, be most appreciated.

Thank you.
 

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It Is What It Is, Dude
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Now the mechanic says the problem might be in the fuel mixture control.
I guess he's talking about the fuel distributor?




GermanStar has remans for under $500, but I would worry about the mechanic's 'it might be'.

Mercedes 107 Fuel System Parts

Not to cast aspersions but perhaps a second opinion is in the offing? I do agree with his assessment of salvage parts in this particular instance.

On a side note, were you to fill out some of your profile about your car, we wouldn't have search your earlier posts to find a model year.:D
 

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1998 SL500, 1959 220S, 1970 280SL
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I hate trying to second guess someone who has their hands on the car.

But ask him what control pressure readings he is getting. If he didn't measure control pressure, find another mechanic.

This would help determine if the problem is in the fuel distributor or the warm-up regulator.
 

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Discussion Starter #4
Sorry, the car is a 1983 model year and I have had it since new.

It is definitely running MUCH better since the filters and plugs were changed, but the distributor issue could be the cause of the hesitancy.
 

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It Is What It Is, Dude
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learnix said:
Sorry, the car is a 1983 model year....

I knew that.:D


...the distributor issue could be the cause of the hesitancy.

But first do as Chuck suggests. This is the warm up regulator (WUR).





You'll find it in front of the air cleaner. It controls fuel pressure to the fuel distributor, hence the control pressures check that Chuck spoke about.
 

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I agree with everything already said, but i would also check the primary fuel pressure. The WUR controls the mixture for sure, but by pushing down on the air sensor by hand you are taking the WUR out of play and forcing the mixture rich and as said, should stumble and die. Either the fuel to the FD is not there or the FD / linkage to the control plunger is toast. Just my thought on the deal.
 
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