Ill start off by saying Im open to suggestions as to what I may be feeling.

The truck
1994 obs 7.3 zf5 2wd 4.10 gears
160 injectors
adrenaline hpop
kc turbo

This past weekend I was towing my gooseneck ( 12k pounds ) up a hill and the further into the pedal I went the harsher the vibration. When I let off the gas and go back in the vibration would go away and then come back.

It first occurred on a back road section, typically around town I use a less hp tune since its easier shifting and not as aggressive pedal sensitivity. As soon as I hit the interstate I switched tunes and didnt experience the issue all the way home, until I switched back to the other tune to take my exit, it was then the truck felt low on power and required alot more throttle than normal to hold speed. if I pressed the pedal more the vibration came back..

I have towed like this for several years, cross country even and never had this sort of experience.

I plan on hooking up my scan tool tonight and going for a drive in each tune to see what ICP IPR and CPS do, but it seems odd that the issues come and go with different tunes.

What are the symptoms of a bad or failing IDM or ICP sensor? could this be masked by one tune and not the other?

one of my first thoughs was axle wrap, but why would this feel like low on power, or change with different tunes


Thanks in advance, I will update as I gather more info

 

Could it be your clutch going south?

 

Thats an interesting idea, I have never had a clutch go south and cause something like that. It almost feels like the truck is running out of fuel under a long uphill pull, and if I back out of the throttle the mechanical pump can keep up again.

I drove around with a scan tool and could not get anything wonky to show up.

 

Maybe the carrier bearing in the drive shaft.

 

That was high on the list of possibilitys, however the driveshaft was fully rebuilt 2 months ago since I had a bad ujoint at the carrier