Help needed from the cat Gurus

I don't know for sure but my guess would be the fuel rate is higher when it is acting up because the ECM is trying to maintain a constant rpm or acceleration but is not getting what it wants because of a mechanical issue. There for it commands more injector pulse width to try and compensate that's why you see the higher gph fuel rate. I agree that the camshaft is the culprit. On second thought was the pin in the cam gear in the proper hole in the cam? (Maybe stuck in old cam).

 

This is a peterbilt? I would put a fuel pressure gauge on the return line. Does this truck have a fuel pressure gauge in the dash? has the snubber come loose from the fuel gauge fitting and causing intermittant restiction to head? That would explain high fuel presure.

 

That is alot of boost pressure for an engine with no load.

 

Thats because they have VGT's

 

The snubber falls out of the fuel pressure fitting in to the outlet of the secondary fuel filter housing, and makes its way up the fuel line to the front of the head. Running out of a bucket would make no difference. The restriction between the filter base and the cylinder head. That white smoke looks like its running out of fuel, that would be why the rack mm is high, and making the gallons per hour rise. Gallons per hour are estimated by rack position. The boost is rising due to increased egt's from poor injection, AFRC limit is rising allowing the fuel rack to increase.

 

I've seen my truck shoot flames out the stacks when it was running out of fuel.