We have a motorhome with the 8.3L cummins and 6spd allison. Its a 95 rated at 300hp and its the P Pump motor. It use to climb hills at 50+mph now the same hills with the same weight or less its lucky to go 30-35. No smoke or anything just lacking power. Could it be something as simple as a fuel or air filter? I'm planning to take it to the cummins dealer later in the week but any hints or help would be appreciated. It seems to idle fine and sounds and runs fine just doesnt have the get up and go it use to. Thanks in advance, Sean

 

Fuel and air filters should be easy enough to change w/o paying $$$$$ at the dealer, try those 1st. Could be plugged fuel line or dead LP.

 

How many miles on it?

 

Also the overflow valve on the IP is a common cause of low power.

Check to make sure the throttle lever is getting full travel, too.

 

it only had 54k miles on it. Got an appointment on friday at the cummins dealer. I'll let you know whats going on. Its my parents motorhome and i'm 2 hours drive from it so i cant just go out and work on it just thought i would ask for some helpful ideas if the dealer cant figure out whats going on.

Sean

 

well it went to cummins today. They checked the air and fuel filter and were fine. Then they put it on their dyno and it is only making 105hp at the rear wheels so they will have to dig deeper. Should know by 5tonight or it will be on monday whats wrong.

Sean

 

Is it idling abnormally high, or surging or stumbiling when you release the throttle?

 

Just bumping this back up, any word from Cummins yet?