460 Ford Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
536 Posts
Discussion Starter · #1 ·
Basically the truck downshifts around 1500rpm when I let off the throttle while cruising.
It did this awhile back and got annoying so I switched out to a full manual vb. I hated that as well so I got a Cheetah vb and also switched from a green stripe modulator to a black stripe. Upshifts are nice but the downshifting is back. I tried adjusting the modulator in and out and it doesnt change much. What could be causing this?
 

·
Registered
Joined
·
2,387 Posts
Took a little to figure out .. When the throttle closes vacuum drops to zero so trans thinks its at full load and downshifts ..
 

·
Registered
Joined
·
128 Posts
One I've come across more than once:

EGR valve hooked direct to manifold vac.

Hmm... I wonder why it runs so rough:):)
 
1 - 9 of 9 Posts
Top