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Got schooled on injector timing by an old timer at the Boise truck show

I was helping a buddy set up our booth and this guy with a 'Detroit Diesel' hat just starts pointing at our display engine. He said, 'Your static timing is fine, but you're ignoring the pump's advance curve under load.' He pulled out a worn notebook from 1998 showing graphs he'd drawn by hand, tracking how a 2-degree shift at 1800 RPM could burn 5% less fuel. I never even thought to check that on a road call. Now I carry a portable scope to verify the dynamic timing, not just the static mark. Anyone else run into this on the newer common rail stuff, or is it more of an old mechanical pump thing?
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3 Comments
wadebailey
wadebailey1mo ago
Have you actually tried logging your injection timing under load on a common rail system, or are you just trusting the ECU's baseline map?
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linda_murphy
Why overcomplicate a simple static check?
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the_james
the_james3mo ago
Wait, you call that simple?
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