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Seems like right around 1850 to 1950 it falls flat on its face while hauling, it really kills your climb when starting up a mtn, does anyone else experience this

 

Maybe a plugged filter ? , because mine's ready to pull the hitch off the truck at 2500-2700rpms. or is it fine above those rpm's, but just flat there.

 

its just dead flat right in that area, above and below are awesome just that little area and I change the fuel filter quite often

 

I notice if I slowly accelerate, I have a slight hesitation at around that rpm. Only for a split second then it keeps pulling. This is with no load. If I'm more aggresive with the throttle I don't notice anything. I too was wondering what it is about that rpm level. I know that's where I usually start to build boost. Any ideas???

 

This is a wild guess, but I wonder if Cummins retards the timing in this narrow rpm range for the emission tests.

Might want to try the tone ring mod or Rokktech sensor to add timing and see if this issue goes away.

MikeyB

 

Hello all, this is the first time that i have replyed to any discussions.I have been reading your posts for months before i bought my last truck.I too have the power problem my truck feels like it is dead when i am pulling heavy.i thought that it was just because it was new but it still feels like it has a power problem. empty it runs fine loaded it feels weak.



05 3500 slt dually 4x4 3.73 6spd.completely stock.

 

I noticed the same thing on mine and then it would take off when past that RPM range. After filing the tone ring it the flat spot in the RPMs was gone. Just a sugestion.

 

slowwheelin what exactly is that????

 

I too noticed the exact same thing on my rig when I first got it. One day I was at the Cummins outlet (buying oil/filters) and asked a tech about it. He said what your seeing is the "sweet spot" on the engine parameters. What is that? He went on to say the engineers designed the engine (5.9) to provide the maximum economy/torque at that rpm range hence the "sweet spot". Put your foot into it a little more and the ECM is reluctant to send more fuel. Is that what you notice. Hey happiness is a locked torque converter right, so you hate to step on it more and have it down shift. What I've noticed since I did the Rokkteck mod is that flat line is now at 2000 to 2100. Interesting what two degrees of timing advance does isn't it?

 

That RPM is also where the pinging sound is most noticable on my truck and if I remember right for most other 04.5's and up. This pinging/spark knock sound seems to just "turn on" right around those RPM's. I've done the tone wheel mod and it hasn't changed the RPM where it's at though. Coincidence???? I sure as heck don't know. Just thought I'd throw that into the pot!!!