jerky in low rpms

[captain ayers]

I have a 96 7.3 powerstroke.
when rmps are around 1000 to 1600 it is real sluggish and in overdrive it is jerky. it struggles when going up a incline and when jerking the speedometer will bounce bout 3-5 mph. i can floor it and it smoothes out until i get upwards toward 2600 rpms then has the jerking motion again.
it has a new wix fuel filter and oil filter and oil is new delco 400 le. i recently changed the fuel restriction/vacuum sensor. i had rotella synthetic but notice it rand a lot rougher so i instantly changed the oil back to delco. that all ive done so far. the motor has about 80000 mile on it. recently replaced rebuid. the truck has 250000 mile on it. any ideas?

[BigFuel]

What is your fuel pressure while idling/driving? Does the speedo bounce at all while cruising?

[captain ayers]

Not sure what fuel pressure is dont have a way to test. Needle only bounces when it starts jerking. Mostly in overdrive when rpms are between 1100 to 1600.

[BigFuel]

Get a cheap tire gauge and stick it on the Schrader valve on the back of the Fuel Bowl. when you are done with it chuck it. Pull the VSS (vehicle speed sensor) out of the rear end, clean it, and reinstall it. It is to the right and slightly above the pinion shaft in the rear end. Below 1600 RPMs the truck will be somewhat sluggish because the turbo is not designed to work under 1800 RPMs.

[Blazin8556]

sounds like torque convertor shudder. mine does it at 40-45 mph. wifes car does it too. i think its amped on the bigger trucks cause of the gearing

[captain ayers]

I think I found my problem my wiring harness on valve gasket has a burnt leg on it.. tomorrow oi will be working on it

[Blazin8556]

Let me know how it goes

[captain ayers]

The wiring harnes was the problem. It running like a champ now