Current Situation-- I have a 98 HR Imperial 40' motorhome with a Cummins mechanical 8.3 @ 325hp.
My problem is no power on a hill from a dead stop. I live in Tennessee in the hills, and due to property constraints when I back my motorhome out of my pole building I have to crank the coach hard to the left once my front end clears the building, I am also going downhill as I back out. After I have backed up as far as I can, to get out of my driveway onto the main road my wheels need to be cranked hard the opposite direction and climb uphill from a dead stop.
I hold my breath every time because now when I bury the throttle the motorhome does not want to move. The engine is flat and I have no boost. After a few tries it usually very slowly starts to move and I am able to get out of my driveway onto the main road. Once I am on the road I climb hills with no issues and seem to have plenty of power, my only issue with power is in the position stated above.
The engine has 48K miles and the only engine repair has been replacing the turbo charger. I do my own maintenance (not a professional) and changed the turbo myself after I was told by a Cummins dealership that it needed replaced.
I had to be towed from my driveway to Cummins because on that occasion I could not get the motorhome to go up the hill. Cummings changed the waste gate and said it is a temp fix to get me home. I changed the turbo when I got home, still did not help much, but now slowly the motorhome climbs. It’s only a matter of time before I will need to be towed again.
What can I do to get the power needed to get up the hill from a dead stop? Waste gate adjustment, fuel pump etc.? I do have a slight exhaust manifold leak, and I have adjusted the valves a couple of times, maybe I did something wrong there. Hard to tell when the problem started since I lived in Indiana (very flat ground) when I adjusted the valves and did not have any dead stop hills to climb with the wheels cranked.
When I changed the turbo I added a boost gauge, and have seen as much as 20 pounds going uphill moving down the
road. All crossovers and hoses/fittings are OK and do not seem to be the problem.
Thank you for your responses and help.