Installed the FASS-2 this morning because I was dead in the water.
That when like a charm.
BUT!!

How can a fuel system upgrade affect my tranny, in a good way.

No more auto shifting like a 6sp from 1st to second anymore!!!!!
Here is that post https://www.dieseltruckresource.com/...ht=auto+shifts

I'm telling you its gone. It pulls hard through 1,2,3 now. still got that crazy lock up thing but I'm just tickled that coming off the line is better.
I still have that C-clip on my workbench, the one suspected to be from the Shuttle Shift Valve.

But hey, things are looking good now!

 

Just a guess but did you disconnect the batteries? Dirty battery connections/grounds can cause all kinds of weird problems.

 

No battery disconnect lately. Did APP reset thing about 2 weeks ago, no help.

But it sure is running properly now.

 

Don't know why it would be shifting better, but im glad you got your truck up and running good now. Hope to see you in Waco on the 12th.

 

I`m just guessing here, but it could be that you never had correct fuel pressure for the truck to run right. By adding the FASS, you have good fuel pressure/volume and the truck is actually running like it should have all the time.

Just a guess....

 

Did you hit it with a hammer? Thats what I do when things don't work right and if that don't work I get a bigger hammer