Hi yall this is my first post and its more of a question.. I have an 01 cummins and i was pulling hay back home(like nothing is even there) but when i shift into fifth gear the turbo just turns off and won't accelerate or nothing but fourth it turns on again. I don't know nothing about diesels or turbos any opinions will help thanks..

 

Welcome.

You need to install a boost guage. Could be your wastegate. Might be a small boost leak. Have you scanned the truck for codes?

 

The turbo doesn't really turn on or off, but is directly related to fuel delivery. It's very odd that 5th has no power, but 4th does. Every other gear is fine as well?

 

It has camshaft sensor when i pull up the codes

 

Most likely you'll find it's not related to what gear your in but where the powerband is. There's nothing mechanical that would relate to fifth gear producing less power unless the tranny is damaged in some way. You could always throw a cam sensor in it, or verify it's wiring/control. but without more information an online diagnoses is almost impossible!

 

maybe the turbo is a little too big for what you are trying to do and just isn't spooled up at that time.what are the mods done to the truck that might help with diagnosing it for ya