C4 Shifting problem

I have a C4 trans behind a 302 ford in a Mustang and does not stay in 1st gear long enough. I mean i dont get 5 feet before it shifts into 2nd... Anyone know what could be the problem and how do i fix it?!

 

There are several vacuum modulators for this trans, and more than one pin that goes in the hole first. Many of the modulators are adjustable, start there.

 

I have an FMX that does the same thing. It actually goes from first to second then third before you can get through an intersection. I tried an adjustable modulator & still can not get it to shift. My ***umption is something is messed up in the governer ***embly. If you get it fixed post your solution

 

Yes,i repair those cars for a living.
Look at the vacuum modulator on the ******.Looks like a ign.vacuum pot.
Its on the end of the ****** on the p***enger side.
If you unplug the hose a small flat blade screwdriver will fit right in.
Turning clockwise will make it shift later.You want 2 rev's clockwise a time and then test again.
If you take it too far there will be no third(direct).Does'nt harm things,just go back
counter clock wise from there.
Having the br*** screw 1/8th in from the surface is always a good starting point.
With your early upshift it might nearly fall out..LOL!

Very few Fords will have a none adjustable unit.In that case just go get an adjustable one from the parts store(all new ones are adj).
But take the old one with you,as there are screw in- and clamped type ones.

have fun,
OldschoolOlli

 

@57Custom:What ol don said:
Been there/done that.Make your own (longer) pin.Doesnt have to win prices.I even used a nail one time,only needs to push a bit.
If you have good shifts,but no third just shorten it from there.
1/16-1/8 longer mostly does the trick!

Ollie

 

I will give that a shot as soon as the weather will cooperate