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Hello all
We had the same problem with our 300SD.
It would lose power after a half an hour of driving.
Especially when going uphill, it seemed.
If we would let it sit for 15 to 20 min it would be OK again for a while.
I also thought it may be crud settling in the bottom of my tank.
So I disconnected the fuel line just before the fuel filter.
And put the open end in a bucket.
And pressurized the fuel tank at the fuel filler cap with compressed air.
I was trying to blast out any crud that may have been at the bottom of my tank or in the fuel lines.
What I noticed was the fuel lines under the tank started dripping fuel.
The old rubber lines that are covered with a braided fabric.
( I call those fabric covered lines " Hitlers revenge " )
( I bet a lot of the old VW Beetles caught fire because of that stuff )
It was impossible to see under normal operating conditions that the lines were letting air into the fuel system under the vacuum of the fuel pump.
I replaced all of the old fabric covered lines with new rubber ones.
Including the return lines on the fuel injectors.
That solved the power loss problem for me.
By the way.
The lines directly under the tank have a pressed on metal retainer, like a hydraulic line does.
I ground the metal retainer off, and there was a hose barb underneath.
I attached the new fuel lines with regular hose clamps.
NAPA had the very small diameter fuel line in stock, to replace the return lines from the fuel injectors.
This has solved the power loss problem for me.
And I hope it will for you also.
Thank you.
Until next time I bid you peace and happiness.
RichC
