Cummins 444 ???

Cummions 444 a fine Motor 10-15 PSI at hot idle is about Normal with worn Bearings might want to roll a set into her. Jake issue and the hang up have a clue what is going on man I love the fact I drove one of these things that was a BEAST. Check in the Injection pump for a weak Governor Hold down Spring if that is bad replace it and also replace the Governor Button with a 6 button. Trust me you will love the Performance gain in the HILLs. What is happening is this your Engine is refusing to go back to Idle also replace the Oil Pump while your replacing the Bearings 444's where notoriuos for weak Cranks unless you had plenty of Oil Volume not Pressure. If you plan on keeping this an using her as a daily worker find an old BC 1 series and get the Water inlets off that motor then Put a High Flow Coolant System on the 444. Put an Air to Air instead of a Water Cooled Intercooler on it. Will lower your Exhaust temp about 100 Degrees and gain you about 50 HP without requiring BIG Bucks. Drove a 444 with over 800 To the Ground.

See mine Snapped a 720HP chassis Dyno like a twig I still had 50 Lbs of Rail Pressure and was still building to the top end of the Powerband when the Dyno let go. Computer said over 850 EST based on setup and seeing how that old girl hammered UP Snowshoe in PA and the Steel Haulers were Pulling over. I knew I had something Big there.

 

Check the return fuel line to see if it is plugged, sounds like the rail pressure is not coming back down quick enough.

 

Never seen a 444 but heard about them

 

Drove a Freightliner Special Edition with a 444 18OD and 3:55's for a month or so in the early 90's. Took it up to 105mph and it still had pedal left. I talked with a couple of engineers when they were building the (then) Freightliner plant in St Thomas, ON. They had built this truck in BC and had an interest on how it was running, so I asked them 'just how fast will this thing run?' - answer = 127mph.

 

Sounds like air in your fuel system. leaky throttle shaft.

 

Check that the throttle lever is tight where it mounts onto the pump shaft. The shaft is splined & the lever is held by a 1/4 bolt. The bolt can loosen & the lever moves on the shaft. Also the lever is hinged to allow it to break over when the throttle shaft hits its stop. The lever has its own spring to hold it straight. The spring can break & allow the lever to flop around & can cause the problems you have.