what is the IVS and how do you adjust it?

did anyone find out what the fix is for this problem?
I have an early 99 that does it bad.

yes sir, push the throttle down some more..... j/k

its a tranny issue

what part of south texas? I'm between houston and galveston. I had the tans. rebuild a few mths. ago but the problem is still there. want to get it fixed but don't know where to start.:-banghead

i'm in the RGV.

i corrected mine by adding the sonnax kit and sending the pcm to Jody.

if i had known better, I would have gotten the valve body from BTS when I had the tranny rebuilt.

More than likely it is in the pedal. If you know someone else around you that has the same pedal assembly you could swap it out and verify. Most programming changes the TPS settings so 1% throttle equates to say 10%, gives a false sense of power so to say. If the pedal positioning is bouncing back between 0 and 10 everytime the pedal moves ever so slightly, I could see where the bouncing would come from.

my 00 f250 with a 6 spd does the same thing, i had started a thread about it but nothing yet, hopefully we find a cause.

I also notice this "surging" or light bucking at around 40mph, its only noticable to me when the motor isnt fully warmed up. I figured it was the injectors or something relate to that...

must not be a tranny thing if a 6spd. is doing it. Mine runs fine up till it goes into overdrive, if you let off and slow done to between 40 and 50 it surges like it doesnt want to downshift unless i give it about 1/2 pedal.