CM2250 Poor fuel mileage

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Also I ran Injector leak test and leakdown was 2090, 6k miles ago it was at 900, and 10k before it was at 340. I checked the rail relief valve and there was not a single drip. Something seems to be deteriating should I be concerned or wait till it gets worse and easier to find? fuel pump was rebuilt 17k ago.
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You might want to check the torque on the quill tubes. I had one that was leaking due to improper torgue. I was losing about 10K in a minute on the fuel rail leak down test and now she is sealed up and and holds above 29K for at least a couple minutes.