My 3500 started with a very sluggish take off, but then shifts perfectly . help

 

Compared to what? Mileage? Last tune up? Did this just start happening? You need to provide more info in order for us to assist you.

 

when we changed the solenoid pressure switch, then it started being sluggish at take off

 

What engine/trans?

 

5.9 engine and Allison Trans. 6 cylinder

 

Ah, der diesel..... All the tubing for the turbo intact?

 

yes, all tubing is intact. It starts off in 2nd gear

 

That would definitely make it sluggish..... getting any trans codes?? I don't know squat about the allison trans.....

 

code says po700

 

That's a pretty generic code, and could mean all sorts of things.... Usually, there will be another code along with it, that points to what the actual problem is. If you don't have another code, reset codes, go for a drive. See if the code immediately resets.