I have a 1996 Monaco motorhome with an C8.3-325MC Cummins 12 valve, (engine serial# 45301020, CPL 2158). 325HP 925 ft.lbs torque. The motorhome sat unused for 5 years or so.
I bought it with unknown, but "looks" like relatively low miles by engine paint and cylinder head combustion chamber condition observed during recent valve job.
It has new Holset HX-40 turbo, new Bosch injectors, oil and filter change newtorktek adjustable overflow valve and new Larry B fuel shutoff valve.
It has the Bosch P7100 P-Pump (Part# 402 736 898).
The engine starts easily and idles great for 30 seconds or so and revs 25 rpm or so, drops 50 rpm or so, idles rough and produces black smoke from then on.
Related or not, the top of the #3 cylinder exhaust manifold near the head will climb to 380 degrees within 5 minutes, while all other cylinder manifolds remain in the 180 degree range.
I've swapped injectors and delivery valves from #3 to other cylinders but the #3 cylinder remains hot and the engine runs rich.
I was going to replace all (6) delivery valves, but the Bosch delivery valve part# 2418552175 does not seem to be available anywhere...in the world.
I'm thinking, I just need to pull the pump and find someone to do a functional check on it and rebuild it if required, but all I hear about is how reliable these pumps are and mechanic friends saying "I don't think that's it..."
I disconnected the muffler to verify it was not clogged. I disconnected the turbo to assure it was not stuck. I actuated the PacBrake on/off, to assure it was not actuated full-time and I disconnected the main fuel line from the 175 gallon tank return line and ran it off a 5-gallon can of fresh diesel to verify fuel quality and return fuel line was not clogged.
Still smokes black and is not usable.
Any suggestions would be greatly appreciated.
I bought it with unknown, but "looks" like relatively low miles by engine paint and cylinder head combustion chamber condition observed during recent valve job.
It has new Holset HX-40 turbo, new Bosch injectors, oil and filter change newtorktek adjustable overflow valve and new Larry B fuel shutoff valve.
It has the Bosch P7100 P-Pump (Part# 402 736 898).
The engine starts easily and idles great for 30 seconds or so and revs 25 rpm or so, drops 50 rpm or so, idles rough and produces black smoke from then on.
Related or not, the top of the #3 cylinder exhaust manifold near the head will climb to 380 degrees within 5 minutes, while all other cylinder manifolds remain in the 180 degree range.
I've swapped injectors and delivery valves from #3 to other cylinders but the #3 cylinder remains hot and the engine runs rich.
I was going to replace all (6) delivery valves, but the Bosch delivery valve part# 2418552175 does not seem to be available anywhere...in the world.
I'm thinking, I just need to pull the pump and find someone to do a functional check on it and rebuild it if required, but all I hear about is how reliable these pumps are and mechanic friends saying "I don't think that's it..."
I disconnected the muffler to verify it was not clogged. I disconnected the turbo to assure it was not stuck. I actuated the PacBrake on/off, to assure it was not actuated full-time and I disconnected the main fuel line from the 175 gallon tank return line and ran it off a 5-gallon can of fresh diesel to verify fuel quality and return fuel line was not clogged.
Still smokes black and is not usable.
Any suggestions would be greatly appreciated.
