shift points . . again

enferno

Member
Jun 20, 2006
418
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289 with a '67 c4.

i backed the screw out on the back of the vacuum modulator as far as it will go, and my car still shifts gears way too high

i have the vacuum line going from the modulator to the vacuum tree on the back of the intake.


could i have a vacuum leak? or is there something else i am missing?
 
krash kendall said:
Do you have a vacuum guage? That is what happens when you have a leak or the line comes off the modulator, or perhaps the modulator itself is bad. Did adjusting the screw do anything?


it did a little. it's a brand new modulator & rebuilt tranny. i do have a vacuum gauge, what should i look for on the intake tree at idle?
 
it shifts from first to second at just about the perfect time, but form 2nd to third my engine has to rev so high it make me nervous.

is this a product of a poorly adjusted intermediate band?
 
enferno said:
it shifts from first to second at just about the perfect time, but form 2nd to third my engine has to rev so high it make me nervous.

is this a product of a poorly adjusted intermediate band?

I'm not familiar with symptoms of mis-adjusted bands so I'll ask the other questions.

Was a shift kit installed? We had one that needed to be shifted manually from 2nd to 3rd--became a real pain in the A#$.

How did the tranny shift before the rebuild (actually before it NEEDED to be rebuilt?)

Is your tranny under warranty?
 
over the years, modulator valves have used different length rods. If the rod you have is the wrong length, it could be causing your problem, if its the longer rod and you need the shorter one. Just an idea.

also, check out the C4 forum at fordmuscle dot com.
 
dennis112 said:
I'm not familiar with symptoms of mis-adjusted bands so I'll ask the other questions.

Was a shift kit installed? We had one that needed to be shifted manually from 2nd to 3rd--became a real pain in the A#$.

How did the tranny shift before the rebuild (actually before it NEEDED to be rebuilt?)

Is your tranny under warranty?



it is under warrenty, and i did not own the tranny before it was rebuilt. it has a stage 1 shift kit