Got a sick M11 Cummins Celect plus, need advice

It's in a '99 International Paystar 5000, 440xxx on the clock. Supposed to be rated at 330hp but it feels like 130hp.. lol. Got to gear down on a the smallest of grades empty.. She's pathetic right now. Recent purchase to haul asphalt (quad axle dump).. 8LL Fuller, 4.89 Rockwells. She SHOULD have more grunt with these gears but, nope.

Things we know:

1. It's sick
2. New fuel and air filters
3. Checked for codes toady, none active, 2 inactive said something to do with voltage and the other, '3 counts' on the Engine Position Sensor.
4. EPS is recent, tag says mid 2012 for manufacture.
5. Engine is smooth, no dead holes, quick starts, no stalling, sounds 'ok' I guess.. Can see a very small amout of black smoke under load. Engine runs right up to the governed 2100.
6. No record of maintainance from previous owner, don't know the last Overhead.

Any ideas?

 

Thanks Truckmechanic, will check and report back..

Blow by is minimal, not a slobbering mess at all. Fairly clean really.

 

CAC would be the culprit. Big ol' crack. Poor little M11 was naturally aspirated with a turbo blocking the flow. lol..

$1600 part not including the core charge..

Fuel pressure checked out good as well as a vac test.. (restriction before pump)

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