Archived 2005 Cummins HO lacking power

[Arebacz]

I have a 2005 Ram 3500 Cummins H.O. With the NV5600 6speed. In the last week or so the truck has suddenly started to feel sluggish and is lacking the power it used to have. No codes and no check engine light. I replaced the fuel filter and the air filter with no changes. Any help is greatly appreciated. Thanks.*

 

[cerberusiam]

Without gauges and\or a scanner and some info it is all guesses. Is it low on bottom end power or top end power?

 

[Arebacz]

Without gauges and\or a scanner and some info it is all guesses. Is it low on bottom end power or top end power?

it's low on both. *it just doesn't feel right. *it feels sluggish. *it used to pull in all rpm ranges like there was no tomorrow and it used to be around 2000rpm when the turbo kicked in that it would throw you back in the seat now it doesn't do that. *i drove it with a computer hooked up and in 2nd gear it had 36psi of boost and in 3,4,5 it had about 45psi of boost. *do those numbers sound right?

 

[p-Bar]

The 36psi sounds right for a stock truck the 45 psi doesn't . any black smoke out the exhaust when footing it? Are you original owner? any other performance boxes on it?

 

[Arebacz]

I am not the original owner. The previous owner had a bullydog kit on the truck but removed it before I purchased it. No black smoke and it's only 36 in 2nd. Also is the 45 psi correct for the HO model?

 

[p-Bar]

45 for stock truck is too high with the stock turbo you go outside the useful envelope of that turbo. Wonder if the original owner screwed with wastegate ? 36 should be about stock setup. What can you monitro with the computer you put on? Can you monitor rail pressure?

 

[Arebacz]

It was the computer at the dealer. I don't have an actual computer myself*

 

[p-Bar]

Ok so I assume they were troubleshooting this problem? Did they check rail pressure?

 

[Arebacz]

I'm not sure. If they did I don't know what the rail pressure was

 

[jhenderson]

The computer might be reading absolute manifold *pressure rather than boost. If so subtract 14.7 psi.*

 

[cerberusiam]

it's low on both. *it just doesn't feel right. *it feels sluggish. *it used to pull in all rpm ranges like there was no tomorrow and it used to be around 2000rpm when the turbo kicked in that it would throw you back in the seat now it doesn't do that. *i drove it with a computer hooked up and in 2nd gear it had 36psi of boost and in 3,4,5 it had about 45psi of boost. *do those numbers sound right?

That is normal for a stock truck and not adjusting for ambient air pressure. If it is making that much boost then it is fueling correctly. If you are still running a stock clutch start thinking upgrade, you may just be slipping it under power.

 

[Arebacz]

i have a southbend dual disc clutch in the truck. *definitely not slipping. *i still can't figure out why it's not running right all of a sudden.

 

[cerberusiam]

Did you get a reading on rail pressure at test time? It might be boosting and still short on fuel as the LP or CP-3 dies.

 

[Arebacz]

i didn't check the rail pressure yet