c4 shifting problems - need to fix it in 36hrs! - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

C0V3R · 12-12-2006, 02:49

So far I have been having no luck working out why my c4 wont shift at wide open throttle. It revs all the way out to 6700 rpm and still will not shift! I have tried playing with the kickdown, and fiddling (rotating 2 times ccw) with the vacuum modulator with very little in the way of results.

The vac modulator does not appear to be leaking fluid - can it still be malfunctioning? It was replaced less than 1500mi ago and seemed to be good for about 1000mi.

I was under the impression that even if the modulator isnt working the governor should kick in at some point (5-6k) and force a shift. I dont think I can go any higher than 6700 to see if its going to shift without endangering my engine.

I am scheduled to goto a track day in 36 hours so any help is much appreciated!!

atec77 · 12-12-2006, 05:49

Quote:

Originally Posted by C0V3R

So far I have been having no luck working out why my c4 wont shift at wide open throttle. It revs all the way out to 6700 rpm and still will not shift! I have tried playing with the kickdown, and fiddling (rotating 2 times ccw) with the vacuum modulator with very little in the way of results.

The vac modulator does not appear to be leaking fluid - can it still be malfunctioning? It was replaced less than 1500mi ago and seemed to be good for about 1000mi.

I was under the impression that even if the modulator isnt working the governor should kick in at some point (5-6k) and force a shift. I dont think I can go any higher than 6700 to see if its going to shift without endangering my engine.

I am scheduled to goto a track day in 36 hours so any help is much appreciated!!

You need to educate your foot.

C0V3R · 12-12-2006, 13:02

Thanks for that useful piece of information.

DANGERXY · 12-12-2006, 13:49

check to see if the hose connected to the modulator is crack/split or leaking in anyway, maybe your not getting any vacuum
if not wind the modulator screw all the way out
other than this could be an internal problem
fluid level?

C0V3R · 12-13-2006, 05:24

I've replaced the modulator, disconnected the kickdown, changed the fluid, added additives, changed the lines all with no success.

I tried doing a neutral/drive drop to unstick the governor and at 3000rpm it would not drop into drive. :roll:

atec77 · 12-13-2006, 17:34

Quote:

Originally Posted by C0V3R

Thanks for that useful piece of information.

It is fact useful , if by lifting the foot you make a shift then you establish paramaters , either the kick down is mal adjusted or you have a spring problem in the valve body , now have you tried lifting the foot a little and does it then shift .

C0V3R · 12-14-2006, 01:26

It does shift if you lift your foot, but sometimes takes a while. I have a feeling its the valve body as I have tried disconnecting the kickdown too.

atec77 · 12-14-2006, 01:54

Quote:

Originally Posted by C0V3R

It does shift if you lift your foot, but sometimes takes a while. I have a feeling its the valve body as I have tried disconnecting the kickdown too.

I suspect it's preasure mal-adjustment , you need a proffesional opinion after all the forum is limited , I belive you have the kick down disconnected , perhaps a different adjustmen might help although normally no cable makes the changes early ( I have not worked on a c4 for ages) so I am not certain , perhaps someone has messed with the preasures or solinoids ?

C0V3R · 12-14-2006, 02:46

I think you're right regarding the professional. I've exhausted pretty much all "easy" options for a hobyist so far.

It was working ok before and noone has touched the solenoids, so I'm guessing the valve body is on its way out or something along those lines.

At any rate I'm now thinking alot more seriously about getting a t56 to replace it.

jas24zzk · 12-14-2006, 04:35

Was talking about my old man tonite regarding this.
His C4 was showing the same problem, but was doing it even before WOT.
Was some dirt in the valve body.

Maybe slightly different as his was a fresh build...but thats not to say....

Jas