Fuel Pump

carlh2269

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W203 C220 CDI 08
Does anybody know what the purpose of the low pressure pump ( A611-090-03-50 ) is on my W203 03 plate C220 CDi?
If its not working correctly what would be the symptons?
This car does NOT have the electrical primer pump in the tank.
 

LostKiwi

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The low pressure pump is also known as a lift pump. Its purpose is to get fuel from the tank to the injection (high pressure) pump.

A failed pump will make the car very sluggish at best and difficult to start.

What symptoms do you have?
 
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carlh2269

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Before it'll start it cranks over for 5-6 seconds and then it'll run as normal.
The garage have replaced all the diesel lines under the bonnet as they say there was air in the lines. To be fair changing the lines has massively improved the starting but it's not quite there yet.
With this cold spell we are having it failed to start but using " easy start " soon got it going.
 

LostKiwi

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Have you checked your glow plugs? It's unlikely to be the low pressure pump.
 
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carlh2269

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Don't think it'll be glow plugs. Since the garage has change the pipes, the improvement in starting would rule out glow plugs. I'm still in the realms of initial diesel uplift or pressure.
 

Frosty149

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Like LK says test the plugs, if only to confirm your thinking.
Poor starting and cold weather? It’s reasonable to suspect more than one contributor to the issue.
 

mersum1es

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these lumps are good to start even without one glow plug (especially in UK climate). If all discussion of this car starting problems would have kept under same topic, it would be easier to follow...
 


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