I am hoping to find some help on a new topic for my dually.

Swapped the engine in the dually and I am running with an SCT 3015 tuner (using the pre-set program for performance) and the truck runs great when you want to go. 80K miles on the engine. new fuel filters/oil/air. When driving aggressive it works great once it gets going, but seems to hesitate a moment to get going. When driving casual at low speeds, seems to feel like an intermittent miss or lack of fuel under gradual take-off, but again when you give more fuel it steadies out.

Can anyone shed some light on what this may be or point me where to start checking things?

DPF and Cat both still present, and clear 3000miles ago.

Much appreciate any help.

 

Tuner programming I suspect

 

My dually has a slight hesitation when romping on it from stop. Most of the 6.4s I've ridden in do if they still have the DPF. If you remove the DPF, the hesitation is gone and the truck has a much better throttle response. My truck is still stock except for the cold side intake pipe, but my work truck has the DPF removed and it performs MUCH better.

 

new info....
Checked DTC's and found several.
P0528 Fan speed sensor
P0480 fan 1 ctrl circuit
P2291 injector control pressure too low

checked connections to fan, Cleared faults - test drove
hesitation was initially gone for 5miles. then was back again.
Checked dtc's again and only 2 showing - P0528 and P0480 for fan.
Is it possible for these faults to cause the hesitation?
with P0528 and P0480... what needs to be replaced? Clutch fan assembly? or is there a simple sensor elsewhere that is not functioning?

With the P2291 dtc I am frustrated as it may require another cab lift to get to the injection pump......

 

You will have to let Senix or one of the others answer that as that is way above my knowledge of these trucks. I hope it is not your injection pump.

 

For the injector it maybe an old code. Just monitrfor now.