Truck Repair: 95 Cummins Turbo 8.3 liter, rv motor, liter engine

Question
Engine is in a 39' RV Motor Home.  Slow to take off and slow going up hills.  Can problems with turbo cause this.  On flat surface will only reach approximately 50 mph in about 1/2 mile.  Can eventually reach speed of 75 mph.  The engine has only 40,000 miles.  Oil and filters changed regularly.  Any information will be helpful and appreciated.  Marilyn  

Answer
Make sure there is not another fuel filter hidden besides the one on the engine.Then check the fuel pump shutdown solenoid for wear in the linkage.The older ones would wear enough not to open the fuel up & cause low power.If that checks out good then I would check the fuel pressure to the injection pump.It should be around 20 PSI using the hand primer on the side of it.